BACKGROUND AND OBJECTIVES: Therapeutic lifestyle modifications including weight reduction and smoking cessation are recommended among overweight or obese patients with acute myocardial infarctions (AMIs). We investigated the factors associated with weight reduction and smoking cessation in post-MI patients. METHODS: Between October 2005 and May 2007, 216 (144 males, 63짹11 years old) of 311 overweight (body mass index [BMI] 23-24.9 Kg/m2) or obese (BMI ���25 Kg/m2) patients who survived and followed up more than 1 year after AMI were included. Weight and smoking status were assessed at both at the time of AMI and 1 year follow-up. Factors associated with weight reduction and smoking cessation were analyzed. RESULTS: At baseline, 112 (52%) patients were obese and 104 (48%) were overweight. The body weight of total patients decreased significantly and 20% had a >3% weight reduction at 1 year of follow-up. Ninety-six (44%) patients were smoking at baseline and 52% of them had quit by 1 year of follow-up. The unadjusted mean weight change varied by the severity of the baseline obesity and smoking status at 1 year of follow-up as was a 1.8% gain in the overweight quitters, 1.8% reduction in the overweight non-quitters, 2.0% reduction in the obese quitters, and 3.8% reduction in the obese non-quitters (p=0.029). In a multivariate analysis, age (odds ratio [OR] 1.084, 95% confidence interval [CI] 1.028-1.144, p=0.003) and smoking cessation (OR 0.167, 95%CI 0.048-0.575, p=0.005) were independent predictors of a weight reduction. The abdominal circumference was a negative predictor of smoking cessation (OR 0.903, 95% CI 0.820-0.994, p=0.037). Only a few (6%) patients among smokers achieved both weight reduction and smoking cessation. CONCLUSIONS: The mean body weight of total patients decreased significantly at follow-up. Smoking cessation and age were independent predictors of a weight reduction, and the abdominal circumference was a negative predictor of smoking cessation. Only a few patients were successful in both weight reduction and smoking cessation. New interventions to support weight reduction and smoking cessation in post-MI patients are urgently needed.