In this review we consider some of the acute and chronic effects of alcohol on human exercise and sport performance. The 1982 position stand of the American College of Sport Medicine on the use of alcohol in sport emphasized that there was little benefit for an athlete. Subsequent literature continues to demonstrate that there are adverse effects on performance. However, the literature is often confusing and disparate. We will attempt to explain the effects and speculate on the possible mechanisms. We divide the review into acute and chronic metabolic and physiological effects of alcohol on exercise performance, primarily in humans. We also review the epidemiological evidence of the associations between alcohol use and problem alcohol behaviors in various athletic groups. Finally, we review the limited data on the effectiveness of exercise therapy in the treatment of alcohol dependent patients. In spite of scientific evidence that alcohol use is, in general, detrimental (or of no benefit) to sport (exercise) performance, alcohol continues to be used by athletes both on a chronic basis and even immediately prior to sports participation. There is some encouraging but limited evidence that student-athlete alcohol use is decreasing and exercise can be effective as part of alcohol rehabilitation.