Pulmonary-renal syndrome (PRS) is diffuse alveolar hemorrhage plus glomerulonephritis, often occurring simultaneously. PRS is almost always a manifestation of an underlying autoimmune disorder such as Goodpasture syndrome. PRS can also be caused by SLE, granulomatosis with polyangiitis, microscopic polyangiitis, and, less commonly, by other vasculitides, connective tissue disorders, and drug-induced vasculitides. Diagnosis is by serologic tests and sometimes lung and renal biopsy. Treatment typically includes immunosuppression with corticosteroids and cytotoxic drugs.