The renal impairments were studied clinicopathologically in 57 patients with progressive systemic sclerosis (scleroderma). Proteinuria, hematuria, azotemia and hypertension, used as markers for renal involvements, were observed in 3 (5.3%), 4 (7.0%), 2 (3.5%) and 6 patients (10.5%) respectively, at the initial examination. Hypertension was increased 2.6 times at the last observation, although the incidence of other three markers have not changed during the follow-up period. Finally, 17 out of 57 patients (29.8) revealed more than one of these clinical markers throughout the study. The decrease of GFR (CThio) was noticed in 3 out of 36 cases (8.3%), however that of RPF (CPAH) in 11 of 36 patients (30.6%), including 5 without abnormal clinical markers. Histological studies were performed in 12 patients. One showed crescentic glomerulonephritis, two membranous nephropathy, and the remaining 9 minor glomerular abnormalities. On the other hand, the vascular changes such as intimal proliferation of interlobular arteries were frequently observed. The frequency of pulmonary involvements, skin ulcer and gastro-intestinal involvement in the patients with renal lesions were not significantly different from that of the non-renal group. The level of RPF was significantly lower in the patients with skin ulcer than that of those without skin ulcer. No significant difference was noticed in the frequency of renal involvements between the patients with or without anti-Scl-70 antibody.