Diffuse alveolar hemorrhage (DAH) is a rare but devastating complication of systemic lupus erythematosus (SLE) with a high early mortality rate. DAH seldom occurs without active organ involvement. Recently, rituximab (RTX), a B cell-targeted therapy, has been reported to be effective for life-threatening autoimmune diseases. We describe a SLE patient who presented with acute respiratory failure due to DAH without other active organ involvement. This condition was dramatically improved with RTX without cyclophosphamide.