The clinical value of oesophago-gastro-duodenoscopy and distal oesophageal biopsies was investigated in 49 patients with angina pectoris and normal coronary angiograms. The results were compared to 24 hour oesophageal pH-monitoring of the patients and of a control group of 22 healthy sons. Macroscopic esophagitis--mainly grade I was found in 31% of the patients and microscopic oesophagitis in 25%. The only major abnormalities were the identification of three peptic ulcers (6%). Median (range) reflux index was 1.3 (0.0-13.4) in the patient group and 2.1 (0.0-9.9) in the controls (p = 0.49). There were no differences with respect to endoscopical findings or reflux index between patients with a positive and patients with a normal exercise electrocardiogram. At a median 36 months post study 38% of the patients had undergone acid secretion inhibitor treatment with an effect on symptoms in only 4%. The study provides evidence that routine oesophago-gastro-duodenoscopy is of limited value in this patient group.