Objective. To evaluate the efficacy of cytoflavin in the complex therapy of disseminated encephalomyelitis in children. Material and methods. A blind, placebo — controlled, randomized study was carried out. Thirty-two patients, aged form 1 to 17 years, received cytoflavin from the first day after admission in intravenous drips in 5% glucose solution during 10 days. The control group consisted of 30 children who received a standard infusion therapy. Clinical and laboratory evaluation was carried out on the 11th and 30th days, MRT was performed before hospitalization and on the 30th day. Results and conclusion. Cytoflavin had a positive effect on the rate of recovery of the majority of neurological symptoms. The average EDSS score decreased by 1.5 times to the 30th day compared with the control group. The complete regression of clinical symptoms and focal changes on MRI on the 30th day was observed in 25% of children of the main group and in 3.3% in the control group (р=0.001). The drug exerted the endothelium protective and antioxidant effects, improved blood rheology and restored the content of circulating endothelial cells, the level of D-dimer and indicators of free radical oxidation to the 30th day of treatment.