In our experience, transplantation of the flexor carpi ulnaris is the single best procedure to improve function of the wrist and hand in cerebral palsy. It aids dorsiflexion and supination and, at the same time, preserves active motion of the wrist. This is highly desirable since finger control may be seriously impaired in cerebral palsy and the additional motion provided at the wrist may be most helpful. In fact, since using this procedure we have found that fusion of the wrist is rarely indicated. A good result from a flexor carpi ulnaris transplant depends first upon the careful choice of the patient for the procedure. Requirements for the best function from the transplant include reasonable finger control preoperatively with passive flexibility of the hand, wrist, and forearm; stereognosis of the involved hand; reasonable intelligence; high motivation of the patient and family; and a thorough postoperative regimen. The difference between a good result and a poor result was often the thoroughness of the postoperative care. The value of both exercise and support for the part cannot be overemphasized nor can one underestimate the importance of the interest and ambitions of the patient and his family. The procedure should be postponed until the age when the individual may be expected to cooperate in the training of the transplant.