Laboratory studies were conducted through bioassay technique to evaluate the toxicity effect of some acylurea insect growth regulators on eggs, larvae, and pupae of potato tuber moth Phthorfmaea Operculella (Zeller). Results indicated that the tested acylureas: hexaflumuron, lufenuron, chlorfluazuron and flufenoxuron beside the conventional insecticide profenofos, as a standard agent, proved high insecticidal activities on P. operculelfa. Hexaflumuron and Lufenuron, however, were more toxic against the three tested stages than chlorfluazuron and flufenoxuron. Moreover, larvae stage. was more susceptible than pupal and egg stages with L050 values ranged from 16.98 to 331.13, 102.33 to 582.34 and 4?8.63 to 1202.26 ppm, respectively.