Anterior Cruciate Ligament (ACL) injuries are prevalent among active individuals, particularly in their late teens and early twenties, and often require surgical reconstruction followed by a long rehabilitation period. The rehabilitation process consists not only of physical recovery but also involves significant psychological challenges. This chapter explores the influence of psychological factors on rehabilitation outcomes in patients recovering from ACL reconstruction, which emphasize the dynamic interaction between emotional, cognitive, and behavioral responses. The chapter discusses how personal and situational factors, such as athletic identity, motivation, and social support, influence recovery. The role of Self-Determination Theory in enhancing intrinsic motivation through the fulfillment of autonomy, competence, and relatedness needs is also discussed. Clinical implications highlight the importance of communication between clinicians and the patients, and the use of patient-reported outcome measures (PROs) to monitor psychological well-being throughout rehabilitation. By being aware of that both physical and psychological aspects influence the rehabilitation, healthcare professionals can better support patients, potentially improve rehabilitation outcomes, and facilitate a successful return to sport.