Primary bladder lymphoma, a rare form of non-Hodgkin's lymphoma that is confined to the urinary bladder, is usually of B-cell origin. This report describes an extremely rare case of primary T-cell lymphoma of the urinary bladder. A 45-year-old man presented with haematuria, dysuria and loin pain. Ultrasonography and computed tomography showed a thickened left bladder wall and left hydroureteronephrosis. A diagnosis of primary T-cell lymphoma of the urinary bladder was made on the basis of clinical, radiological and histological findings. The patient, following transurethral resection, was treated with four cycles of CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) chemotherapy with a good response and remains in clinical remission 12 months after treatment.