Three Puerto Rican siblings with the Hermansky-Pudlak syndrome are described, and the literature on this syndrome is reviewed with regard to clinical factors, pathology, pathophysiology, and management of the disorder. The three patients all manifested oculocutaneous albinism and platelet storage pool disease with a moderate bleeding tendency. The oldest sibling died from restrictive lung disease and another has evidence of reduced functional residual capacity, although he is asymptomatic. None of the patients had evidence of inflammatory bowel disease, which has been reported in some cases. All of the patients had an increased incidence of bacterial infections, and they were anergic. Whether their immunological defect(s) is related to the Hermansky-Pudlak syndrome is not known. Two of the patients were treated with oral vitamin E. Bleeding symptoms in both were markedly reduced, although major changes in platelet aggregation were not seen. Vitamin E therapy did not appear to affect the progression of lung disease in the patient with fatal restrictive lung disease.