We describe a new disease, angiomatosis, occurring in 13 of 50 bottlenose dolphins necropsied after stranding along the Texas Gulf coast. This disease, characterized by nodular proliferation of small thick walled blood vessels diffusely throughout the lungs, is accompanied by vascular proliferation in lung-associated and other visceral lymph nodes. Cavernous hemangiomas, sometimes multiple, may occur in affected nodes. A similar disease, lymphangiomyomatosis, is reported in women of child bearing age. A case reported as lymphangiomyomatosis in a cetacean, may be angiomatosis. In contrast to humans, in which lymphangiomyomatosis is essentially limited to women, dolphin angiomatosis occurs in animals of both sexes, including males with active spermatogenesis. In advanced cases, pulmonary architecture is severely distorted, bronchial cartilages eroded, and airways reduced. The cause of this disease is not determined.