Creatine supplementation has become a common practice among competition athletes participating in different sports over the last few years. The mechanism by which supplementary creatine could have potential ergogenic effects would be an increased muscle creatine and phosphocreatine concentration, leading to a higher rate of ATP resynthesis, a delay in the onset of muscular fatigue and a facilitated recovery during repeated bouts of high-intensity exercise. A critical review of the literature reveals that these ergogenic effects, when found, have been generally shown in untrained subjects performing several exercise bouts under laboratory conditions. The limited body of scientific data available concerning highly trained athletes performing single competition-like exercise tasks indicates that this type of population does not benefit from creatine supplementation. Therefore, the widespread use of creatine ingestion to improve competition performance does not seem to be justified. The potential interest of creatine supplementation for elite athletes could be related to an increased ability to perform repeated high-intensity exercise bouts, either during training or during competition in sports in which repeated efforts are required (e.g. soccer, basketball), but this possibility needs scientific confirmation.