We report four patients, three boys and one girl, with polydactyly and hypopituitarism. All patients had postaxial polydactyly and subnormal growth hormone responses to standard provocative stimuli. Three of these patients had a family history of polydactyly and few other abnormalities. The remaining patient had a major malformation syndrome including a CNS hamartomatous tumor and early death; this patient had no family history of polydactyly. We believe that the association of postaxial polydactyly with hypopituitarism and possible CNS hamartomatous tumors is an important clinical consideration in the evaluation of children with suspected growth hormone deficiency.