Hypersensitivity vasculitis associated with propylthiouracil therapy is a well-documented clinical entity. Although any organ system may be involved, it is most unusual for pulmonary manifestations to be the cardinal presenting features. We report a 72-year-old woman presenting with respiratory failure and hemoptysis following initiation of propylthiouracil therapy for Graves' disease. She had cutaneous stigmata of hypersensitivity vasculitis and diffuse pulmonary infiltrates. The infiltrates improved dramatically after discontinuation of the propylthiouracil therapy and initiation of intravenous corticosteroid therapy.