Thirty-six cases with congenital flexion deformities of multiple digits were classified into six types such as congenital contractural arachnodactyly, distal arthrogryposis, Freeman-Sheldon-like syndrome, congenital aplasia of the extensor muscles of the digits, ulnar drift type and multiple camptodactyly type. Many common clinical features of the hands were observed among these deformities. In eleven cases, 18 hands were treated surgically and were followed up for more than a year. During surgery, complete correction or signigicant reduction of the deformity was achieved in most cases. From these operative findings, it was assumed that the main cause of congenital flexion deformity of multiple digits was contracture of the palmar skin and retaining ligaments of the skin. At follow up, complete correction was achieved in 10 hands, and incomplete or minimal correction in eight hands.