Objective: To study an analgesic role of melatonin in the treatment of low back pain. Material and methods: A study included 178 patients, aged from 40 to 65 years, with low back pain during at least 12 weeks and the VAS score >3. Patients were stratified into 6 groups (3 pairs of comparison). In the first pair, patients of the main group (n=31) received АРТРА (a combination of 500 mg of glucosamine hydrochloride and 500 mg of chondroitin sulfate) in dosage 1 tablet twice a day during 1 month and then 1 tablet during 2 months plus melaxen (3 mg of  melatonin 30-40 min before sleep), patients of the control group (n=29) received only АРТРА. In the second pair, patients of the comparison group (n=30) received АРТРА in dosage 1 tablet twice a day and diclofenac in dosage 25 mg 2-3 times a day, patients of the main group (n=30) received additionally melaxen (3 mg of  melatonin 30-40 min before sleep). In the third pair, patients of the main group (n=29) received АРТРА in dosage 1 tablet twice a day, diclofenac in dosage 25 mg 2-3 times a day and melaxen (3 mg of  melatonin 30-40 min before sleep), patients of the comparison group (n=29) did not receive melaxen. Treatment results were assessed after 3 months for the first pair and after 1 month for the second and third pairs. Results: A significant reduction in pain intensity at movement and resting state was noted in the main groups compared to controls. Conclusion: Possible mechanisms of analgesic properties of melatonin and world experience in chronic low back pain treatment are discussed.