The present experiment was designed to test the effects of practice with relatedness support on motor learning. Forty-five young adults practiced a task in which they were required to learn to swim the front crawl stroke for one length in an indoor swimming pool (25 m) using 50% of the maximal speed. In the relatedness support condition (RS group), the instructions emphasized acknowledgement, caring, and interest in the participants' experiences, while in the relatedness thwart condition (RTh group), instructions emphasized disinterest in the participant as a person. A third, neutral condition (Control group) did not receive specific relatedness instructions. One day after practice, participants completed retention and transfer tests. The RS group demonstrated greater improvement in performance during practice and enhanced learning relative to the RTh and Control groups, while the RTh group showed decreased learning compared with the Control group. Furthermore, RS participants reported higher motivation and greater positive affect than the RTh and Control groups. The present findings demonstrate that relatedness support enhances the learning of motor skills. They also highlight motivational and affective effects that are observed when learners are provided with relatedness support.