Objective: to study the efficacy, safety and tolerability of agomelatine in mixed anxiety and depressive disorder.Patients and methods. Agomelatine was administered to 30 patients diagnosed with mixed anxiety and depressive disorder for 3 months. The patients' condition was assessed using a battery of psychometric methods – the Hamilton Depression Scale, the Hamilton Anxiety Scale, and a short form of the SF-12v2 quality of life questionnaire.Results and discussion. It was shown that agomelatine effectively reduces both symptoms of depression and anxiety, begins to have a therapeutic effect a week after the start of administration, however, the drug shows the best clinical effect when administered for a period of three months or more. The predictors of complete remission on agomelatine therapy in this sample were: the presence of sleep disorders (early and medium, but not late insomnia), a greater severity of somatized anxiety, the presence of complaints of decreased workplace performance and activity.Conclusion. Our study has shown that agomelatine is an effective, safe and well-tolerated drug in the treatment of mixed anxiety and depressive disorder.