Meconium ileus (MI) is the earliest clinical manifestation of cystic fibrosis (CF) in infants. It arises from the intraluminal accumulation of highly viscid, protein-rich meconium, typically present in the terminal ileum as a neonatal intestinal obstruction. Therefore, the clinical symptoms include abdominal distension, bilious vomiting and delayed passage of meconium. CF is caused by mutations in the transmembrane conductance regulator gene (CFTR) located in the long arm of chromosome 7. CF is common in Caucacians, but is a rare disorder in Asian countries, including Korea. We experienced a case of CF combined with MI. Compared with the previous reports of CF in Korea which presented respiratory problems, this is the first case genetically diagnosed as CF with MI during the newborn period.