Most people have had at least one episode of lumbar pain during their lifetime. Pain lasting a minimum of 3 months is defined as chronic lumbar segment pain. Chronic pain affects many activities of daily living, such as getting up, walking, bending over, sleeping, traveling, social interactions, but also work activities. Therapeutic mobilization is one of the frequently used methods in physiotherapy and the optimal choice of therapeutic approach when one wants to influence pain, function and activities of everyday and working life. The purpose of this thesis was to determine the impact of therapeutic mobilization on chronic lumbar segment pain. The study was conducted over a period of three months at the Clinical Hospital " Sveti duh ". The study involved 30 people - patients of the Department of Physical Medicine and Rehabilitation Clinical Hospital "Sveti duh". Subjects were divided into two groups: the experimental group (n = 15) in which, in addition to classical therapy, mobilization of the lumbar segment was additionally performed, and the control group, in which only classical therapy was performed. The Visual Analog Scale (VAS) was used to assess pain, and lumbar segment mobility was assessed by Fingertips to Floor Distance test and SLR test. The quality of life of people with chronic lumbar pain was assessed by the Rolland-Morris Disability Questionnaire and the Oswestry Disability Index. Measurements were performed on the 1st and 10th therapy day. The results of this study show a statistically significant reduction in lumbar segment pain in the subjects of the experimental group (p <0.01), while in other measurements the subjects of the experimental group achieved a better result, but without statistical significance. Therapeutic mobilization reduces chronic lumbar segment pain, but also affects the function and improvement of daily life activities.