Meconium peritonitis results from intestinal wall perforation with meconium spillage into the peritoneum during intrauterine life. Anal atresia is associated with meconium peritonitis and is also associated with cloacal malformation. A female neonate presented with a distended abdomen, anal atresia, and meconium peritonitis as diagnosed by calcification in the peritoneal cavity on abdominal radiograph. Sonography and cystography demonstrated a cloacal malformation with perforation of the hydrocolpos and resultant spillage of meconium into the peritoneum. There was no evidence of further perforation of bowel at surgery. This unusual case of meconium peritonitis is reported.