Objective. To evaluate the efficacy and safety of human placenta extract — laennec infusions in the treatment of patients with confirmed diagnosis of «Chronic fatigue syndrome» (CFS). Material and methods. The study included 38 patients with CFS, randomized into 2 groups: patients of the experimental group (EG, n=24) were treated with 10 intravenous laennec infusions, 4 ml each, 2 times/week, for 5 weeks. The control group (CG) consisted of 14 patients. Treatment efficacy evaluated by the severity of chronic fatigue («The degree of chronic fatigue» questionnaire), state anxiety, depression and anger (Spilberger test) and quality of life (SF-36v2), exercise tolerance (cardiopulmonary exercise test with gas analysis), blood parameters were assessed before, after, and 5 weeks of follow-up. Results and conclusion. The EG patients showed a significant reduction in the index of chronic fatigue, which was accompanied by the significant decrease in state depression, anxiety, improvements in subjective assessment of quality of life, as well as a significant increase in physical performance indices (maximal oxygen consumption, anaerobic threshold, load time to failure, normalization of the lipid «profile» immediately after course of infusions and in 5 weeks follow-up). No changes in chronic fatigue index and other recorded indicators were identified in CG. Laennec did not cause side effects, was well tolerated by all patients.