Epispadias is an uncommon condition in which the urinary opening is on the top of the penis, most often near its base. Epispadias most often occurs in boys with bladder exstrophy but can also develop alone. The causes of epispadias are unknown at this time. It may be related to improper development of the pubic bone. Epispadias is associated with bladder exstrophy, an uncommon birth defect in which the bladder is inside out and sticks through the abdominal wall. Nearly all boys with bladder exstrophy will also have epispadias. Most girls with exstrophy also have epispadias. Epispadias can occur in both boys and girls who are otherwise healthy with no other abnormalities.

Boys with epispadias often have upward curvature of the penis, which at puberty results in the head of the penis pushing against the stomach and creates difficulty for sexual relations. Surgery is done to straighten the upward bending, move the opening to the tip of the penis and correct the foreskin—most often with circumcision.