In 149 patients, a standardized radiologic method for the detection of gastro-oesophageal reflux was applied and compared with the results obtained at endoscopy and by a manometric reflux test. Radiologic reflux was recorded in 53 patients, of whom 25 had reflux without abdominal compression and 51 with compression. At least one of the other two types of examination disclosed pathologic conditions in all but 2 of 53 patients. Oesophagitis was significantly more severe among the patients with reflux observed at radiography. The presence of hiatal incompetence with reflux only to the hiatal hernia but not to the oesophagus was not a strong indicator of gastro-oesophageal reflux disease. Hiatal hernia was present in a significantly larger number of the patients with reflux at radiography than in those without reflux. Increased width of the hiatus gave stronger evidence for reflux disease than in patients with a normal hiatus. Thus, the width of the hiatus also had a bearing on the diagnosis of gastro-oesophageal reflux disease.