The black cutworm Agrotis ipsilon (Hufnagel) (Lepidoptera: Noctuidae) has a wide range of distribution throughout Africa, Europe, Asia, and the Americas. It is a polyphagous insect attacking nearly all vegetables and many important grains in the world. The present study was carried out to investigate the effect of novaluron (a chitin synthesis inhibitor) on the most important parameters of adult performance and reproductive potential of this insect. Both the 4^th instar and 5^th instar larvae were treated with a series of novaluron concentrations (50.0, 25.0, 12.50, 06.25 & 03.10 ppm) via fresh discs of castor bean leaves. The most important results could be summarized as follows. The adult emergence was considerably blocked, regardless of the treated larval instar. Various adult mortality percentages were recorded. Novaluron failed to affect the adult morphogenesis after treatment of 4^th instar larvae, while it exhibited a slight anti-morphogenic effect on the adults after treatment of 5^thinstar larvae only with 25.00ppm. The total adult longevity was generally shortened. The pre-oviposition period was remarkably prolonged. The oviposition period was considerably shortened. The post-oviposition period was prolonged or shortened, depending on the concentration and the treated larval instar. The oviposition efficiency was severely inhibited, in a dose-dependent trend. Adult fecundity was drastically prohibited and fertility was dramatically reduced. The embryonic developmental rate was remarkably retarded, since the incubation period of eggs was considerably prolonged. Therefore, novaluron may be an effective IGR being used in the IPM program against A. ipsilon