Rituximab, a chimeric monoclonal antibody targeted to the CD20 antigen of B cells able to induce antibody-dependent and complement-mediated lysis of these cells, has been reported to be effective in children with NS secondary to MCD or FSGS unresponsive to other immunosuppressive treatments. Rituximab achieved persistent NS remission in a patient with MCD diagnosed at age of 30 yrs who had a history of frequent relapses refractory to treatment with other immunosuppressants. Thus, chronic MCD persisting into adult-years may respond to rituximab and sustained remissions are possible despite long-term disease and after other treatments have failed. Along the same line, rituximab achieved prompt and persistent remission in an adult with steroid and mycophenolate mofetil-resistant MCD and in two patients with FSGS and steroid-resistant NS.