During a period of 6 years, 31 of 54 infants with congenital diaphragmatic hernia survived and were evaluated to study incidence and management of gastroesophageal reflux. At 6 months' follow-up 16 patients had gastroesophageal reflux proven by upper gastrointestinal series; at 12 months' follow-up 11 patients. Three patients having gastroesophageal reflux did not respond to medical treatment and underwent Nissen fundoplication. We conclude that after successful treatment, congenital diaphragmatic hernia is likely to be complicated by gastroesophageal reflux. We could not define a predictive feature for gastroesophageal reflux in the individual patient surviving congenital diaphragmatic hernia.