The association of bilharziasis with membranous nephropathy (MN) has long been debated. The relatively recent use of antibodies against the M-type phospholipase A2 receptor (PLA2R) has been proposed as a valuable tool to discriminate the idiopathic from secondary MNs. Anti-PLA2R antibodies are found in sera from about 70% of iMN patients, in contrast to patients with secondary MN, in whom serum anti-PLA2R antibodies could not be detected. In the current case report, we detected anti-PLA2R antibodies both in serum and renal biopsy from a patient with MN associated with Schistosoma mansoni. This finding confirms the idiopathic nature of the MN and excludes schistosomiasis as the triggering agent of MN. After treating bilharziasis, Ponticelli regimen was initiated without a significant improvement.