The study was carried out on 18 patients with angina pectoris in whom the usual treatment with nitroderivatives and/or Ca-antagonists did not improve or prevent the angina-like chest pain in the absence of unstable angina. The patients underwent the following oesophageal examinations: X-ray, endoscopy-biopsy, manometry, acid perfusion test and 24-hour oesophageal pH ambulatory monitoring, the latter two being made in association with dynamic ECG. The presence of coronary insufficiency had been previously determined by means of ECG and scintigraphic stress tests and, when necessary, coronary arteriography was performed. In 10/18 patients severe oesophageal motor disorders were observed, the most frequent being diffuse oesophageal spasm. In the entire group the lower oesophageal sphincter basal tone was significantly lower than normal. In 14/18 patients a pathologic gastroesophageal reflux was detected: in 2 of these patients a temporal correlation between pain attacks and episodes of gastroesophageal reflux were observed in the absence of ECG modifications. Acid perfusion test induced the angina-like chest pain in another 2 patients without ECG modifications. In conclusion, the angina-like chest pain of these patients is not due to a failure of the antianginal therapy in relieving the coronary insufficiency, but is most probably related to gastroesophageal reflux. This oesophageal disorder may be considered a side effect caused by prolonged therapy with nitroderivatives and Ca-antagonists. In fact, these drugs decrease the lower oesophageal sphincter tone which is the main barrier against the reflux of gastric contents into the oesophagus so favoring gastroesophageal reflux and related disorders, including oesophageal pain.