The aim of this study was to examine whether motivational orientations for a new motor task could be triggered by unconscious determinants. Participants were primed with subliminal words depicting an autonomous, a neutral, or a controlled motivation during an initial unrelated task, followed by working on an unknown motor task. Behavioral, physiological, and self-reported indicators of motivation for this task were assessed. Overall, results indicated a significant impact of the priming condition on all these indicators; whereas the priming of autonomous motivation led to positive outcomes, the priming of controlled motivation led to negatives outcomes when compared with the neutral condition. Implications regarding the priming of unconscious determinants of motivation for sport and exercise are discussed.