Variant angina developed during intravenous 5-fluorouracil therapy in a patient without prior history of angina pectoris. Ambulatory electrocardiography demonstrated S-T segment elevation and ventricular ectopy during pain, whereas no symptoms or S-T segment changes occurred during placebo therapy. Prophylaxis with both nifedipine and diltiazem was successful in preventing recurrence. It is believed that 5-fluorouracil induced coronary vasospasm and that this was prevented by prophylactic calcium antagonist therapy. Drug-induced coronary artery spasm may be the cause of 5-fluorouracil-associated chest pain.