Meconium peritonitis is an aseptic peritonitis caused by spill of meconium in the abdominal cavity through one or several intestinal perforations which have taken place during intrauterine life or early neonatal life. We experienced three cases of meconium peritonitis with ileal perforation in two cases 1 day-old male neonate and 2 day-old male neonate, respectively, which had the chief complaint of vomiting and abdominal distension. Literatures are reviewed, briefly.