Membranous glomerulopathy (MG) is a rare cause of chronic kidney disease. However, after kidney transplantation (KT), despite immunosuppression, it often relapses on the allograft. Herein, we report on a male kidney-transplant patient, aged 27 years, who developed overt nephrotic syndrome 11 months after KT. This was related to relapsing MG, as evidenced by the allograft biopsy, which, in addition, showed CD3 (+) and CD20 (+) interstitial lymphocyte infiltration. The patient was treated with rituximab: 375 mg/m2/week for 4 consecutive weeks, followed by one additional injection every 3 months for one year. Remission was observed before the third rituximab injection. After a follow-up of 42 months, the patient was still in remission, i.e., microalbuminuria of 107 mg/day.