POSTOPERATIVE intestinal obstruction is an unusual, but trying, problem to the abdominal surgeon, and one which has been extensively studied. However, this complication has received little attention in children. Forty-seven instances of postoperative mechanical intestinal obstruction occurring in 43 pediatric surgical patients in the past seven years at the Cook County Children's Hospital were reviewed. The incidence of this complication is obviously increasing as more children survive initial operation for congenital, traumatic, and neoplastic diseases. Clinical Material The 43 patients varied in age from 1 hour to 14 years at the time of initial operation. Eleven were operated upon in the neonatal period; 20 were under one year of age. The interval between the original operation and the first obstructive episodes varied from three days to 11 years; in 20 instances, the interval was 30 days or less. There were 6 white and 37 Negro children; 10 were girls and