Introduction: We evaluated a trainer for improving knot-tying skills using gummy candies (KTG; knot-tying trainer using gummy). To reveal its efficacy, the KTG was compared with a standard knot-tying board by evaluating construct and concurrent validities.　Method: The completion times for knot-tying with the both the trainers were recorded for 18 novices and 18 experts in our university hospital. The evaluation formula was published previously and comprised four items (accuracy, gap, slippage, and breakage) to calculate the total score.　Results: With the standard knot-tying board, the average score was 27.1±22.6 points in the novice group and 37.3±18.7 points in the expert group. There was no statistically significant difference between the groups. With the KTG, the average score was 12.3±20.6 points in the novice group and 36.7±18.3 points in the expert group, with a statistically significant difference (p<0.001).　Discussion: Using the KTG for knot-tying training, it may be possible to acquire knot-tying skills with proficiency-based training, which could improve knot-tying technique.