Clinical features and therapeutical approaches in 10 cases of membranous glomerulonephritis (MGN) have been reviewed in an attempt to identify predictive indices of prognosis, and features distinguishing between idiopathic and hepatitis B surface antigen (HBsAg) related forms of glomerulopathy. Five of these children (age range 8-10 years) had HBsAg associated MGN and the other five (age range 12-16) lacking this antigen were defined as idiopathic MGN. The follow up was nine months to 10 years (mean 4.3 years). All had nephrotic syndrome during the course of their disease. There were no distinguishing clinical features nor any difference in the outcome between these two groups. None of the clinical findings including the presence of HBsAg, adversely affected outcome. All patients in the idiopathic group and three of the five in the HBsAg related group received immunosuppressive treatment. Overall complete remission was achieved in four of the five HBsAg associated patients and in three of the idiopathic patients plus partial remission in one of each group. Immunosuppressive treatment caused no complications, and beneficial results of the treatment particularly in the idiopathic MGN group were observed.