Background and Objectives: This research study was conducted to determine the correlation between the clinicopathologic features and the outcome of membranous nephropathy. Materials and Methods: Data were retrospectively reviewed from all patients with a diagnosis of membranous nephropathy. Demographic, initial laboratory, and clinical findings were collected and the biopsy specimens were reviewed to classify them. To compare means, frequency, and to find correlation, student t-test, non-parametric x2 and Kendall-tau statistical tests were used respectively. A p value less than 0.05 were considered significant. Results: It was found out that during the years 1972-1996, 72 out of 2118 kidney biopsies had been diagnosed as membranous nephropathy. In this respect, male/female ratio was 2:1 (with a range of 1.5-14 years). Meanwhile, 45 out of 72 cases were idiopathic membranous nephropathy (IMN). Furthermore, 27 out of 72 had a secondary cause of the disease due to systemic lupus erythematosus (11 cases) and HBsAg positive (12 patients). The most common features in both groups were nephrotic syndrome and hematuria. In idiopathic and in chronic renal failure groups, remission occurred in 20.9% and 20.9 % of the cases respectively during an averaged 2.13 years of follow up. The statistical test Kendall-tau was used to determine the correlation between initial findings and outcome in IMN. In this regard, a significant direct correlation was found between progression to renal failure and proteinuria (p = 0.009) and/or age (p = 0.01) at the time of admission. For secondary membranous nephropathy, the outcomes were variable depending on the etiology.Conclusion: Proteinuria, age, and underlying etiology are the most important factors determining the renal outcome in membranous nephropathy.