We observed the influence of chronic effect of pyrethroid supermethrin on some reproduction features in Japanese quails. They received 3 different doses (P1 10.7 mg.kg-1.day-1; P2 21.4 mg.kg-1.day-1 and P3 35.7 mg.kg-1.day-1) of the tested substance during 20 weeks. The total health status, reproduction of Japanese quails, the damage rate (degree) of the organs and tissues as well as the determination of residue in the eggs and muscles of the experimental birds showed that pyrethroid insecticide supermethrin can be considered a safe pesticide.