Objective: The objective of this study was to determine if Divaza, a drug with nootropic and antioxidant effects, was safe and effective for the correction of oxidative disturbances and to stabilize cognitive impairment in patients with cerebral atherosclerosis. Study Design: The study design consisted of a 12-week multicenter, randomized, double-blind, placebo-controlled, prospective trial in parallel groups. Setting: The setting in which the study was conducted comprised 10 clinical centers across the Russian Federation. Interventions: Patients were randomized into 2 groups and instructed to take either 2 tablets of the study drug or a placebo 3 times per day in conjunction with basic therapy. Outcomes: The primary outcome was a change in the average endogenous antioxidant potential after the completion of the study. The blood indicators of the oxidative stress (OS) were analyzed at the baseline and then after 12 weeks of therapy using iron-induced chemiluminescence analysis. The Montreal cognitive assessment test was used as a secondary outcome measure to evaluate cognitive impairment at the end of the study. Results: 124 outpatients with a mean age of 60.7 ± 7.6 years were enrolled and randomly assigned to receive Divaza (n = 65) or a placebo (n = 59). An improvement of cognitive function was observed in all patients of the Divaza group at the end of the treatment; this was significantly better than the placebo group (100  vs. 89.5 [89.1]%, respectively, p = 0.0272 [p = 0.0128]). The administration of Divaza restored the activity of the endogenous antioxidant system. The change in the average level of lipoprotein resistance to oxidation after 12 weeks of therapy, compared to the baseline, was significantly higher in the Divaza group (14.8 ± 14.7 [14.8 ± 14.7] seconds latent period vs. 6.4 ± 16.9 [6.9 ± 16.7] seconds in the placebo group (p = 0.007 [p = 0.0107]). Conclusions: Divaza is a safe and effective therapeutic option for attenuating OS and recovery of cognitive impairment in patients with cerebral atherosclerosis.