Vegetarians' dietary practices are of interest to the general population and athletes because of their health- and athletic performance-promoting potential. Well-planned vegetarian diets can meet the energy and nutrients needs of competitive athletes. However, inadequacies of several nutrients may be of concern when planning a vegetarian diet, including protein, essential fatty acids, iron, ... [Show full abstract] calcium, zinc, and vitamin B12. Vegans, especially female vegans, who avoid all animal products, are at greater risk of developing female athlete triad. Constant dietary assessment and nutrient status monitoring should be implemented to prevent deficiencies. Research consistently indicates that habitually consuming a vegetarian diet does not positively or negatively impact physical performance of athletes. Future research needs to focus on properly controlling energy and macronutrient contents of diets, standardizing the sports in which athletes are engaged, and directly evaluating various endurance or resistance performance parameters of vegetarian and non-vegetarian athletes.