Chronic pain is an important medical problem and an urgent issue in modern neurology. Chronic pain affects work capacity and quality of life of patients, their physical and mental health. Previously, the term «chronic pain» was defined as pain persisting after a healing period and protective function of acute nociceptive pain was absent. The 11th revision of the International Classification of Diseases (ICD-11) will officially come into force from January 1, 2022. In the ICD-11, a new definition appeared in the «Pain» section — «Chronic pain» (MG30). Seven main sections for defining chronic pain are a combination of practical applicability with comprehensive classification. Clinically important conditions that were not determined in the ICD-10 will be defined as nosologies, for example, chronic neuropathic pain. Determination of etiological factor and mechanisms of chronic pain should lead to a better diagnosis of chronic pain not only by neurologists, but also other specialists. Allocation of chronic pain in the ICD-11 will improve chronic pain diagnosis, therapy of chronic pain, effectiveness of therapeutic and rehabilitation measures in these patients. Therefore, quality of life, working capacity, physical and mental health will be also improved. The authors describe a new ICD-11 classification of chronic pain.