Herlyn-Werner-Wunderlich syndrome (HWWS) is a rare congenital urogenital anomaly characterized by uterine didelphys, unilateral blind hemivagina, and ipsilateral renal agenesis. We present a very rare case of HWWS-associated cervical cancer in which the presence of a genital anomaly was not noticed until the patient experienced postmenopausal vaginal bleeding. A 74-year-old nulliparous Japanese woman presented with vaginal bleeding. Pre-treatment workup revealed uterine didelphys, obstructed hemivagina/hemicervix, renal agenesis, and cancer development from the remnant-obstructed hemivagina/hemicervix. The patient was diagnosed with HWWS and HWWS-associated vaginal or cervical cancer, treated with radical surgery, and a diagnosis of clear cell carcinoma (CCC) of the uterine cervix was histopathologically confirmed. A literature review revealed an increased incidence of CCC in women with HWWS.