Glomerular lesions were detected in 9 of 10 patients with liver cirrhosis: these lesions consisted of a) thickening of basement-membrane-like material, b) electron-dense deposits in mesangial areas and in capillary walls, c) round areas of rarefaction in the membrane-like material and in some deposits, and d) presence of IgA, with IgG and/or IgM and/or C3, in the deposits. The association of these four abnormalities seems to be characteristic of "cirrhotic glomerulonephritis." The deposits could be the result of precipitation in the glomeruli of either aggregated immunoglobulins or circulating immune complexes.