Primary urethral carcinoma is a rare oncologic condition with limited data to support organ-sparing therapies. Herein, we present a case of primary urethral squamous cell carcinoma in situ of the bulbar urethra treated with intraurethral 5-fluorouracil (5-FU) who exhibited a complete pathologic response observed at the time of dismembered urethroplasty. The clinical features, diagnosis, and treatment course of our case are reviewed. These data may support the use of intraurethral 5-FU for similar cases in the future.