71 patients undergo myocardial revascularisation for Prinzmetal's angina; among them, 50 p. cent are operated upon in emergency according to three ways of anaesthesia: neuroleptanalgesia, analgesic anaesthesia, combined anaesthesia. The authors lay stress on the importance of per- and post-operative complications: electrocardiographic ischemia in 22 p. cent of the cases, severe ventricular excitability perturbations were observed in 21 p. cent, myocardial necrosis in 14 p. cent, cardiovascular collapse in 21 p. cent and hypertensions in 22 p cent. These complications are often associated. In the discussion, the authors underline anesthetic induction as a cause of Prinzmetal's angina in 50 p. cent of the cases. They put the accent on the severity of peroperative crisis followed in 50 p. cent of the cases by serious ventricular excitability perturbations. In 25 p. cent of the cases myocardial necrosis is a complication of the spasm of a coronary artery. In this field, posterior necrosis are more frequent and correspond to the spasm of the right coronary artery. All the patients of this series, except one, develop necrosis in the spastic area (by-passed or not). Per-operative hypertension has no incidence on the occurrence of post-operative complications. Lastly, continuous per-operative infusions of nitroglycerine has been performed in several patients in order to reduce morbidity of this type of surgery.