A 34-year-old man with an 18-year history of hypertrophic cardiomyopathy died of worsening right-sided heart failure. Central venous pressure was greatly increased to 25 cm H2O before death. Postmortem examination revealed features of severe congestive vasculopathy, including those of pulmonary capillary hemangiomatosis in the lungs. Marked proliferation of capillaries was seen chiefly in alveolar septa and extending into pulmonary veins and arteries, causing severe luminal occlusion with recanalization. Diffusely distributed intra-alveolar edema and hemorrhage with collections of hemosiderin-laden macrophages were also seen, which suggested that the pulmonary capillary hemangiomatosis was associated with longstanding chronic passive congestion of the lung. It is possible that severe pulmonary passive congestion may be one of the causes of development of idiopathic pulmonary capillary hemangiomatosis.