Based on the results provided by electron microscopy, membranoproliferative glomerulonephritis (MPGN) has been conventionally categorized as primary type I, type II, or type III. This chapter reviews the most important advances regarding pathogenesis, prognosis, and current therapeutic options for MPGN and some additional MPGN associated conditions. The morphological pattern of MPGN includes a marked and diffuse thickening of the glomerular capillary walls. According to the novel classification, three types of MPGN have been suggested: immune‐complex‐mediated MPGN, complement‐mediated MPGN, and nonimmune complex mediated. The complement system includes three pathways, the classical, lectin and alternative pathways, and patients with C3Glomerulopathy have abnormal control of the alternative pathway of complement. Patients with mutations involving deficiency of regulatory proteins of the alternative complement pathway may benefit from replacement of factors with plasma therapy.