Meconium peritonitis with pseudocyst formation is rare and can be lethal. We report a newborn infant with antenatal sonographic diagnosis of bowel dilatation and giant meconium pseudocyst. Postnatal presentation included a palpable abdominal mass and abdominal distention. Abdominal X-ray revealed a huge egg-shell calcified mass containing air-fluid level. Postnatal sonography revealed a cystic mass with air-fluid level and acoustic shadows. Computed tomography showed a giant communicating cyst with egg-shell calcification, which compressed the other intestinal loops to the posterior peritoneal cavity. Elective laparotomy was performed, and distal ileal atresia with sealed proximal perforation and a giant meconium pseudocyst were found. Resection of the involved small bowel, including the giant pseudocyst, followed by primary end-to-end anastomosis was performed smoothly. The postoperative course was uneventful. Advances in perinatal intensive care mean that neonates can be operated upon under stable rather than critical conditions, and elective rather than emergency laparotomy, and primary anastomosis of the intestine rather than staged enterostomy can be performed.