We describe our experience using color Doppler ultrasound and endoscopy with a pediatric cystoscope to diagnose urethral diverticular cancer previously undetected by a voiding cystourethrogram in a 43-year-old woman. We then carried out a radical excision of the urethral and periurethral tissues including the anterior 1/2 of the vagina while sparing the bladder. The patient has been followed-up for 7 years with no evidence of cancer recurrence.