The results of experiments on rats showed that the psychotropic drug bromantan affects the sexual behavior and pairing activity. A three-day treatment with bromantan (30 and 300 mg/kg, p.o.) predominantly increased the sexual proceptivity, whereas a chronic administration (for 2 months in males and 2 weeks in females) produced a dose-dependent increase in both proceptivity and receptivity. The observed effects are probably related to the dopamine-positive action of bromantan.