Approximately 15-25% of malignant non-Hodgkin's lymphomas (NHLs) are primarily extranodal and only 2.7% of these are located in the genitourinary tract. Only a few particular cases of primary manifestation of NHL in the urethra have been described, most of them in female patients, whereas a secondary involvement occurs more frequently. In the present case a high-grade malignant NHL of the B-cell type was located in the urethra of a 29-year-old male patient. No other manifestations of NHL could be found. After surgical removal of the urethral neoplasm the patient was treated with combined chemotherapy (6 cycles of the CHOP scheme). Thereafter, reconstruction of the urethra by the island flap method of Duckett was carried out. Two years after diagnosis the patient is alive and in complete remission with good functional and cosmetic results of surgery and a normal sexual life.