Thirty-seven replanted digital units and four thumb replantations had a flexor tendon tenolysis at an average of 10 months after replantation. The results were assessed by measuring total active motion, potential active motion, and by the formula of Strickland and associates. The total active motion increased from a mean pretenolysis of 72 degrees to 130 degrees. The potential active motion increased from a mean of 43% to 70% after tenolysis. Both of these improvements were statistically significant (p less than 0.001). The formula of Strickland and associates rated 13 excellent, 11 good, 6 fair, and 11 poor. The thumbs had two fair results and two poor results. Poor results were also seen in crush or avulsion amputations, hands with more than two digits amputated, and those requiring a proximal interphangeal joint capsulotomy. Little difference was found related to the number of arteries or tendons repaired. Complications included tendon rupture and infection. No digits were lost. The results of this study would support flexor tendon tenolysis after replantation of fingers but not replanted thumbs.