Objective To compare differences in the cl inical outcomes between percutaneous pinning with plaster spl int and open reduction and pull ing out wire in the treatment of mallet fingers. Methods From December 2002 to September 2007, 72 patients with mallet fingers were treated. They were divided into two groups: group A and group B. In group A, 38 patients were treated by open reduction and pull ing out wire, 34 males and 4 females, aged (26.0 ± 8.5) years. Among them, 2 patients were injured in the index finger, 11 in the middle finger, 18 in the ring finger and 7 in the l ittle finger. Thirtythreepatients suffered from sports injuries, 5 from fall ing wounds. The average time between the injury and the surgery was(6.1 ± 3.1) days. In group B, 34 patients were treated by percutaneous pinning with plaster spl int, 26 males and 8 females, aged (28.1 ± 10.7) years. Among them, 1 patient was injured in the index finger, 9 in the middle finger, 15 in the ring finger and 9 in the l ittle finger. Thirty-one patients suffered from sports injuries, 3 from fall ing wounds. The average time between the injury and the surgery was (6.3 ± 3.6) days. All the fingers had typical mallet malformation, and X-ray films showed avulsed fractures of distal-segment phalanxes at the dorsal basilar part. Results The operation time was (61.8 ± 12.8) minutes in group A and (7.0 ± 2.6) minutes in group B. All patients in both groups were followed up for 6-24 months (11.9 months on average in group A and 13.2 months in group B). In group A, apart from 3 patients who had flap necrosis and infection, all the other patients obtained heal ing by first intention. One patient had palmar skin ulcer at 6 days after the operation and healed after proper treatment. Thirty-six patients gained bone union at (47.6 ± 8.7) days postoperatively and 2 patients had pseudarthrosis, which improved after reconstruction of the extensor tendon attachment point. According to the total active movement (TAM) functional assessment system, 10 cases were e cellent, 18 good, 8 fair and 2 poor, with the choiceness rate of 73.7%. In group B, all incisions obtained heal ing by first intention without pin-track infection, flap necrosis and migration of the pins and gained bone union at (27.7 ± 3.9) days after the operation. According to the TAM functional assessment system, 19 cases were excellent, 13 good and 2 fair, with the choiceness rate of 94.1%. There were significant differences between the two groups in operation time, compl ications, heal ing time and choiceness rate (P lt; 0.05). Conclusion Percutaneous pinning with plaster spl int is simple in operation and has smaller incisions and fewer compl ications compared with open reduction and pull ing out wire, andproves to be a useful way in the treatment of mallet fingers.