Tackle Index
Knot

Surgeon's Knot

Two lines of similar or different diameter.

Last reviewed 26 September 2026 · Editorial policy

At a glance

What this knot is for

Joins
Two lines of similar or different diameter
Line types
Monofilament and fluorocarbon. Works reasonably with braid to mono but is not the slimmest option for that job.

Reach for it when

  • Quick leader-to-leader or leader-to-tippet joins under time pressure
  • Joining lines of noticeably different diameters
Method

How to tie the surgeon's knot

  1. 1Overlap the two line ends by 15–20cm, running them parallel.
  2. 2Treating the two overlapped lines as one, tie an overhand knot: form a loop and pass both tag ends through it.
  3. 3Pass both tag ends through the same loop a second time to form a double overhand knot.
  4. 4Moisten the knot and pull all four ends — both standing lines and both tag ends — evenly to close it down.
  5. 5Trim the tag ends.
Surgeon's KnotPhoto: Wikimedia Commons

Work on a flat surface with enough line in your hand to pull the knot down firmly, and check the wraps sit neatly before you trim anything away.

Why it works

  • Very quick to tie compared with a blood knot, and far more forgiving of mismatched diameters
  • Reliable even for anglers who tie it rarely

Where it lets you down

  • Bulkier than a blood knot, so it can catch in rod guides or a feeder ring on the cast
  • Not as compact a braid-to-leader join as an FG or Alberto knot
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The tackle this knot ties

The knot itself costs nothing — it joins your line to the tackle you buy. This search shows the general category this knot is tied onto, never a named brand or model.

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Alternatives

Knots that do a similar job

Blood Knot →Double Uni Knot →
Used in

Fishing methods that use this knot

Fly Fishing →Float Fishing →
Keep going

More knots worth learning

Improved Clinch Knot →Palomar Knot →Uni Knot →Double Uni Knot →Blood Knot →Surgeon's Loop →Figure-of-Eight Loop →Perfection Loop →
Check the rules where you fish
Some waters restrict tackle or methods — barbless hooks, lead sinkers, certain rigs and line types. Confirm the rules of the water you are fishing before you use any rig or knot.