A 34-year-old Japanese male was admitted to Okayama University Hospital with severe hypertension, rapidly progressive renal failure, blurred vision, dyspnea and hemoptysis. Clinical diagnosis of malignant hypertension was given and antihypertensive therapy and hemodialysis were immediately started. Renal biopsy was performed on the sixth day in hospital to examine the underlying disease, such as microscopic form of polyarteritis, since the complaint of hemoptysis and pulmonary alveolar hemorrhage was noted by computed tomography of the lungs. Typical pathological changes of malignant hypertension, i.e. fibrinoid necrosis of the afferent arterioles and proliferative endoarteritis at the interlobular arteries were observed. There was no evidence of active necrotizing glomerulonephritis and crescent formation. Renal function was gradually recovered and pulmonary hemorrhage completely disappeared by treatment with antihypertensive agents. The authors report a case of malignant hypertension with a rare complication of pulmonary alveolar hemorrhage and speculate that it may be related to vascular injuries at the alveolar capillary level caused by malignant hypertension.