At the Department of Pediatric Surgery in Graz, 31 boys and 23 girls were operated on for congenital diaphragmatic hernia (CDH) from 1978 to 1994. In 49 patients the defect was on the left, in five on the right side. In 46 cases, the hernia was diagnosed within the first week of life; in eight children at a later date. 19 children (35%) died. 25 of the 35 survivors (71%) came to a follow-up examination on average 9.4 (1-17) years after the operation. 24 h pH-monitoring or manometry and Upper G.I. series revealed pathological gastroesophageal reflux (GER) in 16 patients. Nine children were treated conservatively; in seven patients an antireflux procedure was performed. A thoracic position of the stomach or left liver lobe, presence of a hernial sac, gestational age, prenatal diagnosis, use of a patch or severity of lung hypoplasia did not significantly influence the incidence of GER. In three patients, a hiatal hernia was found. The motility of the diaphragm was documented with M-mode sonography (n = 18); a restricted motility could be demonstrated in five patients. GER is very common in patients after repair of CDH. We recommend long-term follow-up with special interest in respect of GER.