The results of surgery for meconium ileus obstruction (37 cases) at Queen Elizabeth Hospital for Children, London, during the years 1953 to 1970 are presented. The surgical survival was 30% in the years 1953 to 1961, and 70% in the years 1962 to December 1970, inclusive. The long-term survival was 57%. Complications, such as small bowel atresia, gangrene, and meconium peritonitis, were associated with a higher mortality. The adoption of the Bishop Koop operation in 1962 coincided with the increase in the survival rate. An association between meconium ileus and hypertrophic pyloric stenosis was noted.