Between January 1987 and December 1990, 67 neonates were treated for congenital diaphragmatic hernia, symptomatic within 6 h of birth. The mortality rate was 33 per cent. Preoperative stabilization was achieved in 47 patients, all of whom survived initial treatment, although two died later. Stabilization could not be achieved in 20 neonates, all of whom died within 3 days of birth, 18 without undergoing operation and two after early repair. Intensive resuscitation with controlled, delayed operation for congenital diaphragmatic hernia gives long-term results similar to those of urgent operative repair. This approach avoids operation in the majority of those who subsequently die.