Abstract We describe an adolescent female patient born with a complex genitourinary malformation including bilateral duplex system and duplication of the müllerian structures (bicornuate uterus and septate vagina). She presented with a symptomatic hydrosalpinx. The typical imaging of this condition is described along with the issues associated with the differential diagnosis in this complex scenario. The diagnosis of hydrosaplinx should be suspected in patients with complex genitourinary malformations and a pelvic fluid collection. Associated genital and renal anomalies are noted in 30% of cases.