Objectives: Following the development of the Sport Imagery Ability Questionnaire (SIAQ; . Williams & Cumming, 2011), the aim of the present two studies was to more comprehensively examine the relationship between sport-related imagery ability and the functions of imagery and observational learning (OL) athletes report. A second aim was to establish the SIAQ's predictive validity. Design: Two samples of cross-sectional questionnaire data are presented in two studies. Method: For both studies, athletes were recruited from a variety of team and individual sports, ranging in competitive level and years of experience. In Study 1, 117 participants (41 male and 76 female) with a mean age of 24.38 (SD = 9.46) completed the SIAQ and the Sport Imagery Questionnaire (SIQ; . Hall, Mack, Paivio, & Hausenblas, 1998). In Study 2, 221 participants (83 male and 138 female) with a mean age of 22.34 (SD = 7.66) completed the SIAQ and the Functions of Observational Learning Questionnaire (FOLQ; . Cumming, Clark, Ste-Marie, McCullagh, & Hall, 2005). Results: Athletes' imagery ability significantly predicted their imagery and OL use. Moreover, with the exception of performance OL, predictions were stronger when the type of imagery ability closely matched the function of imagery or OL being predicted. Conclusions: As well as demonstrating the predictive validity of the SIAQ, results from both studies support the need to use imagery ability measures that most closely match the type of imagery or OL being used.