Studies using self-talk strategies for performance enhancement in different tasks were selected. In particular, studies were required to report at least one experimental test of the effect of self-talk on task performance. In addition, studies combining self-talk with other mental strategies for performance enhancement were sampled, but only for comparison with studies using pure self-talk interventions. As our purpose was to test the effectiveness of interventions aiming to improve performance, groups or conditions using negative (e.g., Van Raalte et al., 1995) or inappropriate self-talk (e.g. Theodorakis, Chroni, Laparidis, Bebetsos, & Douma, 2001) were excluded. In addition, groups or conditions using assisted self-talk (e.g., R. A. Hamilton, Scott, & MacDougall, 2007) were also excluded as assisted self-talk involves the use ofexternal aids, such as headphones, and was not considered pure self-talk intervention. If there was insufficient data for the calculation ofeffect sizes, the authors were contacted to provide the necessary statistical information. The final pool of studies included studies for which sufficient data for the computation ofan effect size were obtained.