In a prospective case-control study over a two-year period involving 1006 women, 264 women with acute myocardial infarction (AMI), 305 with non-infarct acute coronary syndromes (CAD) were compared with 437 women with no coronary heart disease (Controls), to determine the relationship between cigarette smoking and other risks factors with coronary heart disease. A history of current cigarette smoking was strongly associated with the risk of coronary events for both AMI And CAD (p less than 0.001). 23.9% of patients with acute coronary syndromes were current smokers, compared with only 12.8% among controls. Overall, women smokers had about a two-fold increase in risk for all coronary events. Younger women smokers (less than 40 years) and those between 61-70 years had particularly higher risks (10.3 and 2.7 times respectively (p less than 0.01, p less than 0.02). A dose-response pattern of increased AMI risks (from 2.0 to 2.9 times) among women smokers was also found, corresponding to the number of cigarettes smoked per day (p less than 0.05). Other significant coronary risk factors established were: postmenopausal status (OR 6.5), diabetes mellitus (OR 5.1), hypertension (OR 1.6), family history of premature coronary heart disease less than 50 years (OR 1.3) and use of oral contraceptive pills (OR 1.4). Our results thus emphasize that cigarette smoking is an important determinant of acute coronary events even among Malaysian women.