A case of urethral carcinoma in 15-year-old mongrel male dog is described. Signs of dysuria, urethral obstruction, tenesmus, pain and cough were mentioned. Clinically, the animal was undernourished and showed signs of pain and bladder repletion during the palpation of the abdominal region. Other complementary exams were made such as routine urinalyses, X-ray, ultrassonography and measurement of blood urea and creatinine. Macroscopically, the mucous membrane of pelvic urethra was somewhat irregular, due to the presence of several small white irregular and ulcerated nodules of imprecise boundaries. Similar nodules were found in the lungs and heart. Histologically, transitional cell carcinoma of urethra with metastasis to lung and heart was detected