The purpose of this prospective study was to evaluate the results of primary treatment of flexor tendon laceration in zone II according to Verdan's zone system. Special emphasis was given to the postoperative rehabilitation program. Nineteen patients (23 fingers) with laceration of the flexor tendons in zone II were treated operatively. Twelve males and seven females were included in the study. Their mean age was 28 years (range, 16 to 50 years). In 12 cases a concomitant laceration of the digital nerve was present. In all cases primary repair of all injured tendons and nerves was performed and a dorsal splint was applied. On the third to fifth postoperative day an exercise program commenced involving passive flexion-active extension of the injured fingers. Eighteen (22 fingers) of 19 patients completed the follow-up. The results were evaluated according to Strickland's original classification system. The result was excellent in 15 cases, good in five and fair in two. After primary repair of injured flexor tendons, a program of close follow-up, early protected motion and unrestricted motion of the interphalangeal joints offers the best chance of restoring optimal function to the hand.