Objective. To compare the efficacy and tolerability of monotherapy with phenazepam to complex treatment with the peptide preparation selank and phenazepam in patients with anxiety disorders. Material and methods. Authors explored the anxiolytic effect and tolerability of monotherapy with phenazepam (30 patients) and complex treatment with selank and phenazepam (40 patients) in anxiety-phobic, hypochondriac and somatoform disorders (ICD-10 items F40.2-9, F41.1-9, F45.0-2). Therapeutic effect was assessed clinically and with HDRS, CGI and Spilberger scales. Tolerability was evaluated using the UKU scale. Stroop test and verbal fluency test were used. Quality of life was assessed with the SF-36. Results. The positive effect of phenazepam was achieved earlier in the optimization of treatment with selank on HDRS. The combined treatment decreased the level of undesirable side-effects of phenazepam (attention and memory impairment, asthenia, sedation, increase in sleep duration, sexual disturbances, emotional indifference and orthostatism) during the course of treatment and after the tranquilizer withdrawal. Taken together, the therapeutic efficacy and reduction of side-effects had a positive impact on the quality-of-life of the patients treated with selank as add-on to phenazepam. Conclusion. The results extend therapeutic possibilities of treatment of anxietyspectrum disorders with the combination of benzodiazepine tranquilizers and selank.