Cloacal exstrophy variants are comprised of a wide range of characteristics, of which there are four primary features, including omphalocele, bladder exstrophy, an imperforate anus and spina bifida. The existing literature regarding the differential diagnosis from alternative urinary diseases prenatally are limited. If the bladder is present, defects in the ventral wall may not be visualized with prenatal ultrasound in certain conditions, including oligohydramnios, and differential diagnosis from urorectal septum malformation sequence is a challenge. In order to improve the diagnosis of cloacal exstrophy variants, the present study investigated the misdiagnosis of a cloacal exstrophy variant as a urorectal septum malformation in a fetus by ultrasound and analyzed the reasoning of diagnosis in detail.