Fly Fishing Knots
How to Tie Basic Fly Fishing Knots
Contrary to what you may have been told there are only a few fly fishing knots you should master for most Colorado Fly Fishing. These nine knots below should serve for most other fly fishing except deep sea, steel head or big lake trout fishing. For deep sea fly fishing, depending on the species you are fishing for, you may need to use a steel or wire leader. For steel head or big lake trout, you will need to use a heavier leader than the 2X to 4X base leaders we normally use for Fly Fishing in Colorado. (Frankly, If you become expert at tying the Uni-knot, you may not need any other knot except the "Perfection Loop" for Fly Fishing Colorado.)
Knot Parts
- Tag End -- The short part of the line in which the knot is actually tied. The tag end is the excess portion of the line remaining after a knot is tied and is usually trimmed off.
- Standing End -- This is the longer part of the line that goes to the reel or longer part of the leader you may be working with.
- Turns or Wraps -- A turn or wrap is one complete revolution of one line around another line. Normally achieved by by wrapping the tag end around the standing end or a standing loop.
- Loop -- A closed curve of line formed. Normally formed by bringing the tag end back and along side the standing line. Or by tying a knot that forms a loop. An example would be the double surgeon's loop.
- Double Line -- Similar to a loop except both strands of line are used to form a knot. Pinching a loop closed on the big end forms a double line.
- Overhand Knot -- Break Strength 40 to 75%. While technically a knot, I am mentioning it here because an overhand knot can form part of a more complex knot.
By itself, this is one of the weakest and poorest knots you can make. Improper fly casting will often put an overhand knot in a leader. Sometimes these are referred to as "Wind Knots". Most often the wind had little to do with the knot being in put into the leader. If you get one of these, try to get it out with the needle in your clippers or clip the leader off above the knot and replace the leader section or just replace the whole leader. There is nothing more frustrating than hooking up with a nice 19 or 20 inch fish and loosing it to a broken leader with a "wind knot" in it.
How to tie a simple Overhand Knot
- Form a loop with the standing leader behind the tag end. The tag end pointing to the right.
- Wrap the Tag end 1 times over the standing leader and back through the loop.
- Moisten the knot.
- Pull the standing line and Tag End in opposite directions to tighten the knot.
- The overhand knot is the weakest of the knots but is sometimes used a starting point to tying more complex and stronger knots.
Graphic of a simple Overhand Knot

Knots for Attaching Fly Fishing Line to Leader
- Perfection Loop -- joins the leader to a fly line that has a loop connector installed. Although most leaders today come with a perfection loop knot tied in the leader, you may have to cut off the manufacturer's knot for some reason and retie one of your own.
Perfection Loop Illustration - Double Surgeons Loop -- Used to form a loop in a piece of leader for attaching the leader to the fly line. Similar use as the Perfection Loop. Double Surgeons Loop Illustration
- Needle or Nail knot -- serves the same purpose as the perfection loop. It is a much older way of joining fly line and leader. The needle knot is most often used today to join the fly line and the backing.
Nail Knot Illustration
Knots for Joining Two Pieces of Fly Fishing Leader
- Triple Surgeon's Knot -- This knot is a surgeon's knot with one more wrap through the standing loop before seating the knot. My tests this summer show that this knot is about 95 to 100% break strength. I joined 4X to 6X and 5X to 7X tippet easily with it. The trick is to wet the knot before tightening to seat it. This knot is all I use now to join two pieces of leader of same or dissimilar size.
Triple Surgeons Knot - Double Uni-Knot -- This knot can be used to join two pieces of leader of same or dissimilar size. Tied correctly, this knot will not slip. Using just your hands, it is easier to tie than the blood knot. While I used the blood knot almost exclusively for over 30 years of fly fishing, the Triple Surgeon's knot or the Double Uni Knot are much easier to tie.
Double Uniknot Illustration - Blood knot -- (Break Strength 90 -- 95%) Used to join two pieces of leader of same or different sizes. This knot is also quite good for joining two pieces of leader of different diameter. For example a 4X piece to a 6X piece of leader. This is a more extreme example. Generally the step down would be only one size. 3 to 4 or 4 to 5 or 5 to 6 and so on. For me this knot is the hardest to tie by hand.
Blood Knot Illustration - Surgeons Knot -- (Break Strength 95%+) This knot is used primarily to join two pieces of leader of dissimilar size. Or to attach a shock leader to a fly line. This is a reasonably easy knot to tie but one that is hard to draw.
Surgeons Knot Illustration
Knots to Tie the Fly to the Leader
- Single Uni knot or Duncan Knot-- This is a reasonably simple knot to tie. It can be left as a loop that will tighten down upon "hook up" with a fish or it can be cinched tight to the hook eye right away. If you are going to cinch to the hook eye, make sure to moisten the line so the knot will slide down to the eye and tighten correctly. Once tied correctly, this knot will not slip. It is supposed to be stronger than the improved clinch knot.
Uniknot Illustration - Clinch Knot -- Used to tie the fly to the end of the leader.
Clinch Knot Illustration - Improved Clinch Knot -- (Break Strength 95%) Used for same purpose as the Clinch Knot but has better breaking strength.
Improved Clinch Knot Illustration
While all of these knots can be tied by hand, a knot tying tool can be of assistance in learning to tie them. The knot tying tool is especially useful for the nail knot and the blood knot. If you don't want to carry another piece of equipment around, your can learn to tie all nine of these knots by hand with a little practice.
If you want to simplify your fly fishing, learn
- the Perfection Loop for attaching a leader to the fly line
- the Triple Surgeons Knot for attaching two pieces of leader together
- the Uniknot or Improved Clinch Knot or the Eugene Bend for attaching your fly to the tippet.