We report a case of deep vein thrombosis and acute pulmonary thromboembolism that occurred during chemotherapy for urethral carcinoma. A 68-year-old woman suffered from dysuria for a period of 2 years. When the symptoms worsened, a urethral catheter was placed and she was referred to our hospital for further examinations. Imaging analysis revealed a urethral tumor with multiple metastases. Pathological diagnosis on a specimen obtained from transurethral resection of the urethral mucosa was urothelial carcinoma and combined chemotherapy with gemcitabine and cisplatin was administered. On day 6 of the second course, the patient collapsed and was found to be in cardiorespiratory arrest. Cardiopulmonary resuscitation was successful and she received percutaneous cardiopulmonary support. Computed tomography at that time revealed a pulmonary embolism and deep vein thrombosis in the right popliteal vein. After her condition improved, an inferior vena cava filter was inserted to avoid further thromboembolism. The patient decided to continue the chemotherapy despite this episode. After the fourth course of combined chemotherapy, the urethral tumor and metastatic tumors were downsized, and she could urinate as she did before.