We report the case of a 76-year-old woman who was referred to our hospital for a gradually worsening cough and renal dysfunction. Although pneumonia was initially suspected, imaging findings of the lungs revealed diffuse alveolar hemorrhage at a later date. Renal failure developed and hemodiafiltration was performed on the 9th day. Rapidly progressive glomerulonephritis with crescent formation was diagnosed by renal biopsy. This case presentation has important clinical implications because uncategorizable pulmonary-renal syndrome (PRS) without the presence of ANCAs and anti-GBM antibody is extremely rare and has high rates of morbidity and mortality. No treatment has been established.