Obesity adversely affects most cardiovascular (CV) risk factors and is strongly associated, probably as an independent risk factor, with most CV diseases. However, substantial evidence points to the existence of an "obesity paradox," in that overweight and obese patients with established CV diseases typically have a better prognosis than leaner patients with the same CV disease. Despite this paradox, we believe that the "weight" of evidence still supports efforts at purposeful weight loss in both primary and secondary CV prevention.