The present study investigated the mediating role of motivational self-talk strategies (i.e., mastery self-talk, extrinsic self-talk, and efficacy enhancement self-talk) in the relationships between achievement goals and academic engagement (i.e., involvement, withdrawal in the face of difficulties, avoidance of challenges, and disruptive behaviors) among 1096 10th grade students (43% male) in a selective Chinese high school. Structural equation models showed that total and desirable effects of mastery goals were partially mediated by motivational self-talk strategies. Performance approach goals were maladaptive and only weak partial mediation was found through motivational self-talk strategies. A similar pattern was observed with performance avoidance goals. Mastery self-talk and efficacy enhancement self-talk were related to positive patterns of engagement while extrinsic self-talk was related to maladaptive patterns of engagement. Theoretical, cultural, and practical implications are discussed.