A 14-yr-old boy whose primary kidney disease was FSGS developed severe recurrence of proteinuria immediately after a second living-related kidney transplant. Despite pre- and post-operative PP and immunosuppressive treatment consisting of steroids, CycA, daclizumab, and MMF, daily protein excretion and serum creatinine increased. We therefore administered rituximab on the fourth day of transplantation. He received four weekly doses of rituximab (375 mg/m(2)/dose), which resulted in a rapid clearing of circulating CD19-positive B cells, and remission of proteinuria was achieved six wk after the first rituximab treatment. Graft function was excellent six months after transplantation with proteinuria of 8 mg/m(2)/h. We conclude that rituximab may be an effective treatment for post-transplant recurrence of FSGS.