Symphalangism is an uncommon syndrome characterized by fusion of the interphalangeal joints of the hands and feet. The fusion can involve the proximal or the distal joints; however, involvement of the proximal interphalangeal joints is more common. Symphalangism often is associated with several other skeletal and nonskeletal abnormalities. Analysis of the pedigrees of affected families reveals this trait to be autosomal dominant. The authors present the case of a 9-year-old boy with bilateral symphalangism of the proximal interphalangeal joints in the fingers and toes. His father is affected similarly. A comparison of these cases with those published in the literature indicates that although the radiologic appearance of symphalangism appears disabling, the fused phalanges seldom cause disability or loss of function of the hand. Surgical intervention is not required in most patients. The father and son reported also had capitellar hypoplasia and subluxation of the radial head associated with limitation of elbow flexion and extension.