This study examines the preference of 64 out-patients for either a barium meal or an upper gastrointestinal endoscopy. The sequence of the examinations was randomized to avoid order bias. An initial preference for a barium meal of almost two-to-one, with 53% having no preference, was changed after the investigations to a preference for endoscopy of two-to-one with 5% having no preference. The use of mild sedation and the skill of the endoscopist had a major impact on the patients' opinion of the endoscopic procedure, and on their choice of examination for any repeat study. There was little agreement between clinical diagnosis and the result of investigation, but clinicians tended to accept the reported result of the investigation, especially if the result was abnormal. Despite a change in diagnosis in 34 of 49 patients there was little change in management as a result of the investigations, supporting the view that young patients with dyspepsia may be managed with symptomatic treatment initially, and without investigation. This study lends further support to the view that endoscopy should be the investigation of choice in patients with persistent dyspepsia, especially those whose age or infirmity may make barium examination suboptimal.