The Hermansky-Pudlak syndrome consists of tyrosine-positive albinism, a defect in the second phase of platelet aggregation, and widespread accumulation of a ceroidlike pigment in tissue. Pulmonary fibrosis has also been reported. In this paper, we describe two families with documented Hermansky-Pudlak syndrome in which four members, two from each family, developed granulomatous colitis. This adds another disease entity to those associated with this syndrome. We discuss possible connecting links between these disease expressions.