Surgery is still the main treatment for congenital polydactyly, and the aim of surgical reconstruction is to obtain a thumb with excellent function and appearance. A systematic assessment of polydactyly is required prior to surgery, including bone stress lines, joint deviation, joint activity and joint instability, size and development of finger and nail. Bone shape, joint incongruency, and abnormal tendon insertions must be corrected completely, in order to obtain good function and to avoide secondary surgery. Bilhault-Cloquet procedure can reconstruct the size of the finger and nails. Fine manipulation can improve the postoperative nail deformity, so that the reconstructed nail reaches a satisfactory aesthetic score.