Obesity is increasingly more common in postindustrial societies, and the burden of childhood obesity is increasing. The major effects of obesity on cardiovascular (CV) health are mediated through the risk of metabolic syndrome (insulin-resistance, dyslipidemia, and hypertension), such that an absence of these risk factors in obese individuals may not be associated with increased mortality risk. In individuals already diagnosed with chronic CV disease (CVD), the overweight and class I obese have significant associations with improved survival. However, this effect is attenuated by increases in cardiorespiratory fitness. The negative effects of obesity on CV health manifest as accelerated progression of atherosclerosis, higher rates of ventricular remodeling and a higher risk of associated diseases, including stroke, myocardial infarction, and heart failure. The most effective therapies at reversing CVD risk factors associated with obesity have been dietary changes with exercise, especially through structured exercise programs, such as cardiac rehabilitation.