Since 1985, 7 symmetrical thumb polydactylies were treated with Bilhaut-Cloquet operation (V-shaped wedge out). As for Wassel's classification, two cases were type I (duplicated distal phalanx but not epiphysis) and two type IV (duplicated proximal and distal phalanx), and three type II (duplicated distal phalanx and epiphysis). Preoperatively, thumb polydactylies must be symetric and cut articular surfaces be accurately approximated. As for Wassel's type IV polydactyly, preoperative angiogram was done for detection of any vascular anomalies and tried not to damage the anomalous digital arteries of thumb. There was no postoperative complications. All patients and their parents were much satisfied with the postoperative results, but somewhat limited thumb motions were remained. In type I (2 cases) the average IP joint range of motion was 39°, in type II (3 cases) the average IP joint range of motion was 22°, and in type IV (2 cases) the average range of motion of IP joint was 21° and MP joint was 26°.