The comparative central effects of polypeptide drugs cortexin and cerebrolysin were studied in Wistar rats after introduction into the cerebral ventriculi in a dose range from 1 mg to 10 mg and 100 mg and after intraperitoneal injections in a dose of 1 mg/kg. Both drugs produced a moderate psychostimulant action, cortexin being more effective as compared to cerebrolysin. This effect was confirmed by all methods studied, including open field, elevated plus-maze, intruder-resident, and self-stimulation of the lateral hypothalamus. It is suggested that cortexin and cerebrolysin have similar mode of action, while cortexin is more effective than cerebrolysin. A difference between the intraventricular and intraperitoneal effects of drugs was that in the first case both drugs produced a moderate anxiolytic action, while in the second case an anxiogenic effect was registered. The central anxiolytic effect of drugs is probably related to a nonspecific action of polypeptides administered via brain ventriculi.