To evaluate the effect of practice duration on accuracy, retention, and confidence when learning how to tie basic surgical knots. Prospective study. Fifteen first-year veterinary students. Students were randomly assigned to a 2-week practice (TWP) or an 8-week practice (EWP) to learn how to tie surgeon's, strangle, and miller's knots. Students' knot-tying accuracy and confidence were evaluated immediately after training, at an intermediate time point (2-6 weeks postpractice), and at 12 weeks postpractice. Students who had been trained during an extended period tied the strangle knot correctly more often at all assessments (P = .025). The ability of students trained for 2 weeks to tie the strangle knot correctly decreased over time (P = .028). These students lost some confidence (P = .03) and repositioned suture more frequently (P = .03) while constructing the strangle knot at the final time point compared with students trained for 8 weeks. Students who completed TWP felt more confident at placing surgeon's knots than friction knots at the final assessment period (P = .0164 miller's knot, P = .0056 strangle knot), whereas confidence did not differ between knot types for students who completed EWP. All students felt less confident with their knot-tying skills at 12 weeks postpractice. Training for 8 weeks rather than for 2 weeks resulted in superior knot tying skills. Students' confidence decreased 12 weeks after training. Prolonged distributed practice is recommended to train students for more complex tasks such as placement of a strangle knot.