How to Tie a Uni Knot (Step-By-Step With Video)

An easy-to-follow, step-by-step guide with photos and a video tutorial to show you how to tie a uni knot the easiest way possible for all uses.

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In this article, I’ll show you how to tie a Uni-knot. This versatile knot can be used in many different fly fishing situations. I’ve even used it to catch sailfish and tuna.

If you’re a one knot kind of angler, the Uni-knot is the one for you. And most of all, it’s dependable. In some of my tests on thigh leader, only the Nail knot and Homer Rhodes have produced better. However, they cannot be used in as many different applications.

Fly Fishing Knots

Watch The How to Tie a Uni Knot Video

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Uni Knot History

A version of the Uni-knot was first published in The Ashley Book of Knots in 1944. In this book, it was shown as having only 3 passes. However, it may be altered with many more, depending on the material used.

Other names for the knot include the Gallows knot, Duncan loop, and Grinner knot.

A fellow angler and explorer, Edward Truter, first showed me this knot on a fishing trip to the Red Sea. It immediately appealed to me as it was easy to tie, incredibly strong, and could be used on various tippet sizes and leader material.


The beauty of the Uni-knot lies in its versatility. With this one knot, you can attach a hook to tippet material, join two different tippet or leader sizes together, and attach the backing to a fly reel. I even use the Uni-knot as a loop knot for fly fishing bonefish.

How To Tie a Uni Knot To a Hook

Dig into your fly tying kit and take out a hook to practice the Uni Knot with. The Uni-knot may be used on the smallest of tippets (7X or 8X) to the thickest fluorocarbon leaders. You may also use the knot to form a loop to attach the fly. This knot will enable the fly to move freely, giving it great action in the water.

uni-knot attaching hook_step9

Double Uni-knot

The Double Uni-knot is used to join two lines together. These may be lines of any kind, including braid, thing fluorocarbon, or thin monofilament. Most combinations, within reason, will work.

In essence, you are creating two knots that are pulled against each other. The one knot prevents the other knot from slipping through.

I use this knot on a daily basis to create step-down leaders or to extend tippet length. I also use the knot to tie in bright-colored leader material into the existing leader to increase its visibility.

See Also: How To Set Up a Fly Reel

Let’s Get Started!

How To Tie a Uni-Knot

In this section, I will show you how to tie the Uni-knot in both of the above mentioned applications. It’s very simple and quick. This tutorial will teach you how to tie and use the uni knot in a myriad ways that will be very useful for any fly fisherman or woman.

First Method: Attaching Hook To Leader

Here’s how to attach a hook, tippet ring, or swivel to a line using the Uni-knot. This is one of the most common uses of the uni knot and once you have it, it’s very easy to do.

Step 1: Hold The Hook

uni-knot attaching hook_step1Hold the hook with your right hand and allow free access to the hook eye. As you will see, for the purpose of this tutorial I’m using thick string material and a metal clip.

If you watch the video above, you’ll see me tying the uni knot with a hook and fly fishing leader.

Step 2: Thread The Line Through

uni-knot attaching hook_step2Thread the line through the bottom of the hook eye. When you’re out on the river, it can be a bit difficult to quickly thread the line through the hook eye, especially on smaller flies.

In this case, I recommend ensuring you have a clean, sharp cut on the leader so that it’ll pass through the eye more easily.

Step 3: Pull The Line Through

uni-knot attaching hook_step3If you’re practicing the knot for the first time, pull enough line through – I would say about 4 inches.

Once you get the hang of the knot, you’ll be able to use less line length. The line that has been pulled through is called the tag end.

Step 4: Left Hand Pinch

uni-knot attaching hook_step4Pinch both the lines (tag end and the line going to the reel) with your left-hand thumb and forefinger about 1 inch from the hook eye.

Now you have the line secured and you’re ready to start actually tying the uni knot.

Step 5: Form a Loop With The Tag End

uni-knot attaching hook_step5Bring the tag end around to the hook to form a loop. Pinch the loop at the hook-eye with your right-hand thumb and middle finger.

I like to bring the hook around from the right side and under the rest of the line near the hook eye as illustrated in the photo to the right.

Step 6: Wrap The Tag End Forward

uni-knot attaching hook_step6Wrap the tag end forward around the two lines 5 times. Make sure that the wraps do not cross over each other.

Sometimes it’s easier to make use of your mouth and your two hands while completing this step.

Step 7: Pull The Tag Tight

uni-knot attaching hook_step7Pull the tag-end forward so that it tightens the knot up. However, do not pull it completely tight as the loop is far too big at this stage.

Just leave it so that it stays in place, but isn’t fully seated so that you can move onto the next steps in this tutorial.

Step 8: Wet The Knot

uni-knot attaching hook_step7Wet the knot using saliva or river water. This will ensure that it pulls tight neatly and that the line doesn’t burn itself.

Many anglers forget this step, but it really does make for a much more secure and stable knot in the end, so it’s best to get in the habit now.

Step 9: Seat The Knot

uni-knot attaching hook_step9Pull the live line (going towards the reel) until the knot is seated. This is a very strong knot, so depending on the strength of the tippet or material you’re using, you should be able to pull it quite tight to test it, particularly if you still have a long tag end protruding from the knot itself.

Step 10: Trim Off The Excess Tag

uni-knot attaching hook_step10Cut the tag off using a pair of scissors, nippers, or pliers. I have found leaving a small tag works best. Do not trim the tag off completely flush with the knot.

Of course, always be careful when snipping off excess tags not to snip the knot itself, or the active leader material.

Second Method: Joining Two Lines

Joining two lines with a Double Uni-knot is easy and provides a solid and dependable connection. This is a little bit more complex than simply attaching a hook, but once you get the hang of it it’s really just as easy to do. Here’s a step-by-step guide.

Step 1: Prepare The Two Lines

uni-knot two lines_step1Place the two lines against each other. For the beginner, they should overlap about 8 inches. The two line’s ends must be at opposite sides of each other.

Step 2: Left Hand Pinch

how to tie a uni knot step 2Pinch the midpoint of the overlap between the thumb and index finger of your left hand. This is the same in Step 4 in the section above.

Again, it just helps you to set yourself up for continuing the rest of the steps and ensuring everything is in place.

Step 3: Form a Loop With The Left Tag End

how to tie a uni knot step 3Bring the left hand tag end around to form a loop. Pinch the loop with your right-hand thumb and middle finger to form a loop approximately 1 inch long.

This is the equivalent of Step 5 in the section above.

Step 4: Wrap The Tag End Forward

uni knot tutorial step 4Wrap the tag end of the loop you just formed forward around the two lines 5 times. Make sure that the wraps do not cross over each other.

Make a mental note of which way you’re wrapping the line, as you’ll be wrapping in the opposite direction in later steps.

Step 5: Pull The Tag Tight

tying a uni knot step 5Pull the tag-end so that it tightens the knot up. However, do not pull it completely tight as the loop is far too big at this stage.

The knot should look relatively clean and shouldn’t loosen at all when you release tension from the lines.

Step 6: Form a Loop With The Right Tag End

learn to tie a uni knot step 6Now it’s time to repeat the same process with the other tag end, except this time you’ll be wrapping in the opposite direction.

To begin, bring the other tag end around to form a loop. Pinch the loop with your left-hand thumb and middle finger to form a loop approximately 1 inch long.

Step 7: Wrap The Tag End Forward

tie a perfect uni knot step 7Wrap the tag end of the loop you just formed forward around the two lines 5 times. Make sure that the wraps do not cross over each other.

As mentioned earlier, these wraps should go in the opposite direction, so if you previously were wrapping away from you when the line is in an upward direction, it should be coming towards you now, or visa versa.

Step 8: Pull The Tag Tight

this is how you tie a uni knot step 8Pull the tag-end so that it tightens the knot up. However, do not pull it completely tight as the loop is far too big at this stage.

Now you’ll have two identical looking knots a few inches apart on the line and you’re almost done attaching the two lines using the Uni Knot.

Step 9: Lubricate Both Knots

tying the perfect uni knot step 9Lubricate both knots with saliva. This will make the two knots seat easier and prevent the damage of the two lines.

This is especially important when attaching two lines because there is a lot of friction when pulling these two knots together and you want to make sure that they seat correctly.

Step 10: Seat The Knot

uni-knot two knots_step10Pull the two live ends to pull the knots together. Pull until they have seated. Ensure to test the knot thoroughly.

This is an extremely strong knot when tied correctly, so you can give both ends of the line a good tight pull to test. Make sure the knot is very secure before moving to the next step.

Step 11: Trim Off The Tag Ends

uni-knot_on_leader-11Once the knot is seated and tested, trim the tag ends off. Do knot cut them flush with the knots. Once the tag ends are removed, test the knot again.

You can cut the uni knot tag ends quite close, but I like to leave a small amount protruding for extra safety, particularly when attaching two thine lines like leaders, or leader to tippet.

The Completed Uni Knot

uni-knot two knots_step10

Now You Know How To Tie a Uni Knot

As you can see, the Uni is very easy and simple to tie.

As the saying goes: “If you can’t tie knots, tie lots.” Do not try and figure this knot out when you’re out on the water. Practice the knot thoroughly at home until you know how it feels and looks like when seated properly. Only then, start using it.

Please leave any comments or questions at the bottom of the page. Let me know which knots you prefer and if you like the Uni-knot.

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Pierre is a fly fishing guide and professional photographer who has guided and hosted trips for top fly fishing outfitters. Since being introduced to fly fishing over 21 years ago, he has travelled, fished and guided across the globe. He has extensive knowledge on specific gear and tackle selection for various salt- and freshwater species. Some of his writing work includes blogposts for Alphonse Fishing Company and African Waters.

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