Heavy proteinuria with the nephrotic syndrome may occur in association with a wide variety of primary and systemic diseases. In adults, approximately 70 percent have a primary renal disorder such as minimal change disease, focal segmental glomerulosclerosis (FSGS), and membranous nephropathy. Rituximab therapy, which selectively targets B cells, may be an effective alternative therapy in adult patients with steroid-dependent/ steroid-resistant nephrotic syndrome due to primary renal disorders. More studies are necessary to characterize further the type of patients who have nephrotic syndrome and could benefit from rituximab therapy, as well as the optimal dosages and the mechanisms of action of rituximab in this disorders. Patients treated with rituximab experience few adverse reactions.