Ankylosing spondylitis, Morbus Bechterew, is an progressive inflammatory rheumatic disease which doesn't affect only joints, but the whole organism as well while inflammatory back pain occurs. Changes occur in the internal organs, but the main characteristic is the ossification of soft connective structures. As the disease progresses, flexion contractures may also appear while the physiological curves of the spine turn into pathological changes, and the patient develops the „skier's stance“. The causes of the disease haven't yet been discovered, but there is a connection between the occurrence of ankylosin spondylitis and the presence of the HLA-B27 antigen, which is present in the vast majority of patients. The gender of the patient also plays a big role, due to men getting diagnosed with ankylosing spondylitis more often than women, and the first signs of the disease usually appear in early adulthood. The diagnosis of ankylosing spondylitis is established by carrying out a detailed anamnesis and functional examination. Various tests are performed, such as X-rays, laboratory tests, magnetic resonance imaging, computed tomography and diagnosis based on the New York criteria. While in rehabilitation, the very education of the patient is important, therefore it is important to familiarize him with the nature of the disease and explain to him the importance of carrying out exercises and maintaining correct posture. Before determining a physiotherapy plan, various tests and measurements are carried out to determine whether certain characteristics and limitations of spinal mobility are present. The plan is set according to the goals set after the evaluation and includes movement therapy, hydrotherapy, electrotherapy, thermotherapy, cryotherapy, therapeutic ultrasound, diathermy and manual therapy. The disease affects each patient differently, and for this reason it is crucial to have an individual approach to each patient and work out a physitherapy plan depending on the patient's possibilities and inabilities.