A 58-year-old man used spray-type detergent in his bathroom for 3 h and developed bloody sputum the next day. He visited the emergency department of a hospital. A physical examination and an esophagogastroduodenoscopy were performed, but there was no evidence of abnormalities. He referred to our hospital 1 week after the symptom appeared. A chest X-ray and a CT scan revealed diffuse ground-glass opacities in the bilateral lung fields. Bronchoalveolar lavage fluid showed fresh bloodlike fluid containing hemosiderin-laden macrophages. We succeeded in diagnosing his illness as detergent-induced alveolar hemorrhage. Although a variety of diseases are associated with alveolar hemorrhage, this disease sometimes advances rapidly, and the prognosis tends to be very poor. In our case, the patient recovered without steroids and remained symptom-free after discharge. In conclusion, we encountered a rare case of alveolar hemorrhage induced by detergent.