Context: Tennis induces a decreased internal rotation range of motion at the dominant glenohumeral joint. The effects of self-myofascial release have not yet been investigated to restore glenohumeral range of motion. Objective: This study aimed at investigating the effects of self-myofascial release on shoulder function and perception in adolescent tennis players. Design: Test–retest design. Setting: Tennis training sport facilities. Participants: Eleven male players participated in this study (age: 15  y; height: 173.1 [11.1] cm; mass: 56.0 [15.1] kg; International Tennis Number: 3). Intervention: During 5 weeks, the players performed their regular tennis training. During 5 additional weeks, self-myofascial release of the infraspinatus and pectoralis muscles was implemented 3 times per week after the warm-up of the regular training session. Main Outcome Measures: The primary outcome was glenohumeral internal rotation range of motion. The secondary outcomes were perceived shoulder instability and tennis serve accuracy and velocity. Results: Adding self-myofascial release allowed an increase of 11° (2°) of internal rotation range of motion at the dominant glenohumeral joint (P < .001) and a decreased perception of shoulder instability (P = .03), while maintaining tennis serve velocity and accuracy. Conclusions: Implementing self-myofascial release on infraspinatus and pectoralis muscles 3 times per week during 5 weeks improved dominant glenohumeral internal rotation range of motion in tennis players. It can be used as a strategy to preserve the mobility of this joint.