The surgical management of 28 patients with intestinal obstruction due to "uncomplicated" meconium ileus has been reviewed. These patients were treated at the Los Angeles Childrens Hospital in the period from 1942 through 1962. Meconium ileus is an obstruction in the terminal ileum of a newborn infant, caused by plugging with abnormal inspissated, tenacious meconium. The term "uncomplicated" is used here to exclude all patients with associated intestinal atresia, stenosis, volvulus, malrotation, perforation, or peritonitis. Almost without exception, patients with meconium ileus have cystic fibrosis of the pancreas, but only about 10% of patients with cystic fibrosis develop meconium ileus. Rickham has recently reported a small series of cases of meconium ileus occurring in children in whom subsequent detailed studies failed to reveal evidence of cystic fibrosis of the pancreas. It is remarkable that this syndrome is confined almost exclusively to the newborn period. Although the pancreatic achylia and other