Abstract: Objectives The primary objective was to examine the efficacy of a kinesthetic imagery intervention on the sport confidence of three professional flat-race horse jockeys, with the secondary objective of examining the relationship between performance and sport confidence.Design A multiple-baseline across participants research design was employed.Methods The State Sport Confidence Inventory [SSCI; Vealey, R.S. (1986). Conceptualization of sport confidence and competitive orientation: Preliminary investigation and instrument development. Journal of Sport Psychology, 8, 221-246.] was administered twice weekly, prior to a total of 23, 25, and 27 races for participants 1, 2, and 3, respectively. In addition, performance data were collected on each SSCI data collection day. The kinesthetic imagery intervention consisted of six kinesthetic imagery sessions, twice weekly during a 3-week period. The intervention was introduced after race 7, 9, and 11 for participants 1, 2, and 3, respectively. Approximately, 1 week after the end of the data collection, participants completed a postexperimental questionnaire.Results ITSACORR [Crosbie, J. (1993). Interrupted time-series analysis with brief single-subject data. Journal of Consulting and Clinical Psychology, 6, 966-974.] was employed to analyze the sport confidence data. The results of ITSACORR along with visual inspection, demonstrated a significant increase in sport confidence for participants 1 and 3, and a non-significant increase for participant 2. Kendall's tau b correlations failed to find a significant relationship between performance and confidence.Conclusions The results are discussed in terms of the value of kinesthetic imagery as a tool for athletes to practice and develop. Furthermore, this study demonstrates the ability of ITSACORR to provide a statistical analysis for serially dependent single-subject data.