Nicotine patches are commonly used by people who try to quit smoking. Because high doses of nicotine may increase heart rate and potentiate cardiac arrhythmia or ischemia, its use in patients with coronary artery disease was investigated. The objective was to assess the cardiovascular safety of nicotine patches in patients with coronary artery disease (CAD) who try to quit smoking. The study was conducted in a double-blind, placebo-controlled, randomized fashion over a 2-week period. One hundred and six patients with CAD who wished to stop smoking and were taking part in a smoking cessation program were included. Fifty-two patients received nicotine patches (Nicotinell) and 54 received placebo patches. The cardiovascular effects of nicotine patches were assessed by repeated ambulatory ECG monitoring (AEM) and exercise testing. There were no changes in the resting heart rate and in the systolic or diastolic blood pressure between the screening and the two phases of the study in both the Nicotinell and placebo groups. Repeated 48-hour AEM revealed that there were no significant changes in the number and duration of ischemic episodes in both groups. There was no change in the frequency of atrial or ventricular arrhythmias. Exercise duration and time to 1-mm ST-segment depression increased in both groups during the double-blind treatment phase. More patients in the Nicotinell group claimed tobacco abstinence compared with the placebo group (27% vs. 13%). The use of nicotine patches did not cause aggravation of myocardial ischemia or arrhythmia in coronary patients and therefore can be used as a method to promote smoking cessation in this high-risk group.