Anterior cruciate ligaments are one of the constituent parts of the knee joint. Their role is to stabilize the knee and prevent the tibia from slipping anteriorly. An ACL injury is very common among professional athletes as well as among the rest of the population. The mechanisms of injury are most often associated with landing activities, sudden and strong hyperextension of the knee, sudden changes in the direction of movement, sudden stops and/or the action of direct force. In the diagnostic assessment, in addition to a detailed history, a clinical examination using the Lachman test, anterior drawer test, pivot shift test, along arthroscopy and magnetic resonance imaging are used. The patient's condition (age, degree of injury, personal activities, accompanying injuries) determines operative or conservative treatment. The main goal of physiotherapy after the anterior cruciate ligament reconstruction is to restore the functional status of the injured to the state before the injury. Immediately after an injury or reconstructive surgery, it is necessary to direct physiotherapy procedures to remove pain, reduce edema, restore mobility, and increase muscle strength. In the pre-operative phase, muscle strengthening exercises are applied to speed up recovery in the post-operative rehabilitation phase. After the injury itself, as well as after surgery, inhibition of the quadriceps due to pain and effusion is common, and it is extremely important to direct the procedures to reduce the hematoma, using cryotherapy, compression, and elevation. Postoperative rehabilitation is divided into six phases when it is important to follow an individually adapted protocol for patients with team cooperation with the operator.