Chronic ankle instability is a frequent locomotor condition associated with pain and instability of the same joint. This condition not only makes any form of physical activity difficult, but also reduces the individuals' quality of life. Out of a total of 33 joints in the ankle for movement, the lower and upper ankle joints are the most important. The upper leg joint enables plantar and dorsiflexion, while the lower leg joint performs abduction and adduction movements as well as external and internal rotation. The musculature of the ankle is divided into intrinsic, which is located on the foot itself, and extrinsic, which is located on the lower leg, but has grips on the ankle. Chronic ankle instability begins with an ankle sprain. Due to insufficient treatment and rehabilitation, instability occurs, which causes further sprains. Sprain on the lateral side of the ankle is the most common, while damage to the talofibular ligament is the most common. The initial task of a physiotherapist is a quality physiotherapy assessment. It begins with an anamnesis, which obtains basic information from the patient, and is followed by an objective assessment, which assesses joint function and ankle musculature strength. Specific tests such as the talar tilt test, palpation and gait assessment are also applied. By collecting data, we get feedback on the impact of the condition on everyday life. After getting to know the patient's condition correctly, the intervention phase begins. The initial acute state of ankle sprain is treated with the "PRICER" method. By calming down the acute phase, the physiotherapist begins with range of motion, strength, coordination, balance and proprioception exercises. Rehabilitation can be further enhanced with bandaging techniques, kinesiotaping and easy flossing methods. Patient education is an integral part of therapy. The patient is educated about activities that can cause injury again, but also about activities that have a favorable effect on his health. Educating the patient about performing exercises after the end of rehabilitation is one of the most important aspects of rehabilitation.