Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple organs involvement. Bladder involvement (Lupus cystitis) is a rare manifestation of SLE, and occurs in association with gastrointestinal manifestations. We report a case of lupus inters-titial cystitis with bladder irritation and bilateral hydroureteronephrosis in an adolescent female who was treated with intravenous methylprednisolone pulse therapy followed by oral pred-nisolone and mycofenolate mofetil (MMF). Her symptoms ameliorated, and the hydrouretero-nephrosis improved. She was presented again with systemic flare up of the disease together with hydrouretronephrosis, but without bladder irritation symptoms. The diagnosis of lupus cystitis was confirmed by radiographic abnormalities, cystoscopy and bladder biopsy