Rhabdomyolysis is a rare but potentially life-threatening disorder. The long list of known risk factors includes trauma, drug intoxication, alcoholism, hyperpyrexia, vascular occlusion, infections, electrolyte imbalances, heat intolerance, seizures, severe exertion, and substance abuse. Exercise-induced muscle damage is commonly experienced after physical activity, and different studies showed that the amount of protein consumed seems to affect its magnitude. In this regard, some concern has been raised about vegetarian athletes. We present a case of rhabdomyolysis that occurred in a young athlete following a poorly planned vegetarian diet. The athlete experienced progressive weakness and intermittent muscle aches particularly in the legs, malaise, episodic tachycardia, and nausea. Serum creatine kinase was markedly elevated (9952 units/liter), and a mild alteration of transaminase values was observed. The patient was hydrated intravenously and recovered fully within 5 days. The controlled introduction of a planned amount of protein in the diet allowed the athlete to carry on with his sporting activity fully without any further muscle problems. Physical exercise mainly engages the muscular system, and a balanced diet is essential to ensure the energy demands and the anabolic response. A vegetarian diet per se is not associated with detrimental effects in athletes, but an optimal protein intake should be achieved through careful planning with an emphasis on protein-rich plant foods.