An 8-year-old male dog was presented with a peri-urethral intrapelvic mass with the characteristics of a sarcoma on computed tomography and cytology evaluation. A two-step procedure leading to a permanent urinary diversion was performed. During the same procedure, the caudal pelvic urethra and mass were resected and an extrapelvic anastomosis of the pelvic portion of the urethra to its penile portion was performed after passage of the pelvic urethra through the inguinal canal. The procedure successfully produced a tension-free end-to-end urethral anastomosis and no complications were observed during the postoperative period. Histologically, the lesion was reported as a narrowly excised liposarcoma. A 4-week course of curative intent of radiotherapy was initiated 2 weeks after surgery. Eight months later, the dog was free of clinical signs.