Alloferon 1 is an insect-derived peptide with potent antimicrobial and antitumor activity. It was isolated from blood of an experimentally infected insect, the blow fly Callifora vicina. Synthetic alloferon 1 reveals a capacity to stimulate activity of NK cells and synthesis IFN in animal and human models. Moreover, it was demonstrated antiviral and antitumor activity of alloferon 1 in mice. There are no data on influence of alloferon 1 on central nervous system. The aim of present study was to determine an effect of alloferon 1 on rats' central nervous system by some behavioral tests: open field test, hole test, score of rats irritability, and determination of memory consolidation in the water maze test. Moreover, a probable antinociceptive effect of alloferon 1 in rats was determined by a tail immersion test and hot plate test. Experiments were performed on female Wistar rats. Seven days before experiments, rats were anesthetized with ketamine and xylazine and polyethylene cannulas were implanted into the right lateral brain ventricle (i.c.v.). On the day of experiment, alloferon 1 dissolved in a volume of 5 μL of saline was injected directly i.c.v. through implanted cannulas at doses of 5-100 nmol. It was found that alloferon 1 had slight effect on locomotor and exploratory activity, induced some decrease of rat irritability and a weak impairment of rats memory (only at the low dose of 5 nmol). On the other hand, the higher dose of this peptide exerts significant antinociceptive effect. Obtained results indicate that alloferon 1 do not exert any evidently toxic effect on central nervous system in rats. Therefore, alloferon 1 may be good new drug with antitumor and antinociceptive activity.