Ten patients with classical angina pectoris due to coronary artery disease were exercised on a bicycle ergometer with a load of 60 w until they developed the onset of angina pectoris. They each performed this exercise four times in a nonsmoking state and four times after smoking a cigarette made from the leaf of Lactuca sativa (lettuce leaf). Smoking a non-nicotinized cigarette did not significantly affect the systolic blood pressure, the diastolic blood pressure, or the heart rate in any of the patients. None of the patients developed angina significantly sooner if he smoked a non-nicotinized cigarette before exercising.