In a prospective study in 1224 patients referred for upper alimentary endoscopy, reflux oesophagitis was found in 195 (16%) of the patients and hiatus hernia in 249 (20%). In patients with reflux oesophagitis a coexisting hiatus hernia was found in 68%. The weight-for-height index (W/H1.8), which expresses the degree of overweight, was significantly higher both in patients with hiatus hernia and in the patients with reflux oesophagitis, indicating an overweight of approximately 5% in both groups. The overweight was most pronounced in oesophagitis grades 1 and 2, whereas in patients with severe oesophagitis (grade 3) body weight was normal, possibly owing to weight loss caused by dysphagia and excessive regurgitation. The results support the view that adiposity is associated with both sliding hiatus hernia and reflux oesophagitis and that hiatus hernia plays a role in the development of reflux oesophagitis.