ABSTRACT The study was aimed at assessing the effect of complex therapy including cytoflavin on the dynamics of the clinical presentation and some values of endogenous intoxication in patients with psoriasis suffering from neurological and cardiovascular diseases. We analyzed the results of treatment of 70 patients, who we distributed in two groups depending on the treatment regimen. Group 1 patients (comparison group, 35 patients) received standard therapy, and group 2 patients (study group, 35 patients) received complex therapy with cytoflavin at a dose of 2 tablets BID 30 minutes before meals for 25 days (evening intake of the drug no later than in 18.00). The control group consisted of 20 clinically healthy donors. In addition to the standard clinical and laboratory examination, we assessed the levels of malonic dialdehyde (MDA) and Fe-induced MDA in plasma and erythrocytes, diene conjugates and ketones, catalase in plasma and erythrocytes and superoxide dismutase in plasma. Lipid reserve for peroxidation in blood plasma and erythrocytes (%), peroxidation index in plasma and erythrocytes, and the ratio of catalase in erythrocytes to catalase in plasma were calculated. The analysis showed that patients with psoriasis develop endogenous intoxication syndrome (high values of MDA and Fe-MDA in blood plasma and erythrocytes, diene conjugates and diene ketones) with underlying suppression of antioxidant protection (low values of erythrocyte catalase, superoxide dismutase, and lipid reserve for peroxidation of blood plasma). Complex therapy including cytoflavin corrects the endotoxicosis parameters (decrease in plasma level of MDA by 29.88%) along with increase in activity of erythrocyte catalase by 16.97%, superoxide dismutase by 30.3%, and 2.43-fold increase in lipid reserve for peroxidation of plasma (p<0.001). Inclusion of cytoflavin in the basic therapy for psoriasis leads to decrease in dermatological index of the symptomatic scale by 71.18% and PSS index (Psoriasis Severity Score) by 77.32%.