The basic purpose of this study was to determine and describe motivational differences related to gender in athletes in Greece. This research is of great importance because a systematic examination of how different types of motivation (i.e., intrinsic vs. extrinsic) are associated with sports engagement is imperative for sustaining interest in sports. The main research objectives were (a) to examine, whether athletes’ gender affects their overall self-determination perception, and (b) to investigate the existence of significant motivational differences between athletes, related to their gender. In this study, the Sport Motivation Scale 6 (SMS-6), a revised form of the original well-known Sport Motivation Scale (SMS), was used. Demographic data were also obtained about the participants: gender, age, and parents’ sports history. Results revealed a high overall level of self-determination perception for the participants. Also, athletes were more motivated by Intrinsic Motivation than by Extrinsic Motivation. These findings can help sport teams to establish a more motivating coaching design. Additionally, the improvement of self-determination perception level will help athletes to externalize their enthusiasm, boost their intrinsic motivation, and improve their performance.