The discovery of the M-type phospholipase A2 receptor (PLA2R) as a major antigen in idiopathic membranous nephropathy (iMN) was a breakthrough in understanding the pathogenesis of this disease, establishing iMN as an autoimmune disease. Subsequent studies confirmed that detection of circulating antibodies against PLA2R was positive in approximately 70% of incident iMN patients. We discuss several studies that have suggested the potential role of measuring PLA2R antibodies for clinical practice. Recently, it has been shown that the presence of PLA2R antibodies supported a diagnosis of iMN, changes in antibody levels were related to clinical disease activity, disappearance of antibodies preceded and predicted subsequent decrease of proteinuria and high titers of antibodies were associated with a low likelihood spontaneous remission.