Schistosomiasis mansoni has been well documented as one of the causes of infectious glomerulopathy, with mesangiocapillary glomerulonephritis being the most frequent lesion observed in this condition. Twenty-one patients with hepatosplenic schistosomiasis mansoni and biopsy-documented mesangiocapillary glomerulonephritis (MCGN) were studied and compared with 19 patients with the idiopathic form of MCGN. Nephrotic syndrome was the most frequent clinical presentation in both groups. At the time of diagnosis nine patients with hepatosplenomegaly (4 with associated arterial hypertension) and 12 (8 with arterial hypertension) among the patients with idiopathic MCGN had renal insufficiency. At the end of the follow-up period 16 patients with hepatosplenic schistosomiasis and MCGN (75.2 months) and 15 with the idiopathic form (52.1 months) had renal failure. Also, when compared at 48 months of follow-up, no difference in renal function could be detected in both groups. No benefits related to anti-parasitic treatment in the schistosomiasis group and immunosuppression therapy in either group could be documented. The progression of the renal disease, as assessed by the reciprocal of serum creatinine versus time, and the survival curve, were not different between the two groups. It is concluded that MCGN in patients with the hepatosplenic form of schistosomiasis mansoni is a progressive disease not influenced by anti-parasitic or immunosuppressive therapy, and presents a clinical course similar to that of the idiopathic form.