We report a rare case of uterus didelphia with left hematocolpos and ipsilateral renal agenesis, associated with contralateral vesicoureteral reflux and chronic atrophic pyelonephritis. In the literature 9 cases of uterus didelphia with left hematocolpos but without concomitant reflux and recurrent bacterial pyelonephritis are reported. The embryogenesis of müllerian duct abnormalities, associated clinical findings, including abdominal tenderness and pelvic mass, diagnostic modalities of cystoscopy, excretory urography, laparoscopy and hysterosalpinography are discussed. Early accurate diagnosis and treatment will decrease morbidity and unnecessary surgical procedures.