We describe three patients with acute renal failure after the onset of gross haematuria. In all patients a presumptive diagnosis of rapidly progressive glomerulonephritis was made and immunosuppressive therapy initiated. A renal biopsy was performed in two patients, which showed evidence of IgA nephropathy. Extracapillary proliferation was seen in a few glomeruli. The most notable abnormality was acute tubular necrosis with intraluminal erythrocytes and cell debris. In the third patient, who was known to have longstanding glomerular haematuria, acute tubular necrosis was considered likely after review of the urinary sediment. Despite the fact that immunosuppressive therapy was stopped, renal function rapidly returned to normal in all these patients. We feel that our patients and additional literature data demonstrate that in patients with glomerular disease a reversible acute renal failure can occur that is caused by acute tubular necrosis mediated by haematuria. Recognition of this entity will prevent unnecessary long-term immunosuppressive therapy.