A 2-day-old male (Premie, Large for gestational age(LGA), Intrauterine period(IUP) 33 weeks, birth weight 2,955 gram) was transferred with marked abdominal distention, bilious return via the orogastric tube, respiratory difficulty, and generalized edema (hydrops fetalis). He was born by cesarean section to a 36 year-old mother. Antenatal ultrasonogram at IUP 31 weeks demonstrated multiple dilated bowel loops suggestive of intestinal obstruction. There was no family history of cystic fibrosis. Simple abdominal films disclosed diffuse haziness and suspicious fine calcifications in the right lower quadrant. Barium enema demonstrated a microcolon. Sweat chloride test was not available in our institution. At laparotomy, there noted 1) a segmental volvulus of the small bowel with gangrenous change, associated with meconium peritonitis, 2) an atresia of the ileum at the base of the volvulus, and 3) the terminal ileum distal to the volvulus was narrow and impacted with rabbit pellets-like thick meconium. These findings appeared to be very similar to those of a complicated meconium ileus. In summary, the ileal atresia and meconium peritonitis seemed to be caused by antenatal segmental volvulus of the small intestine in a patient with probable meconeum ileus.