Latent effect of LC₅₀ of Growth Regulators (IGR's)(Teflubenzuron, Lufenuron, and Flufenoxuron ) against pink bollworm Pectinophora gossypiella (Saund.) under laboratory conditions was studied. Tested compounds were evaluated against one-day-old eggs of P. gossypiella. LC_50s were 33.17, 18.65, and 14.36 mg/liter, for Teflubenzuron, Lufenuron, and Flufenoxuron, respectively. The biological effect of these compounds on larvae, pupae, and adult emergence resulted from treated eggs was studied. The obtained results showed prolongation in development periods of larval and pupal stages resulted from treated eggs compared with control. Results indicated prolongation in adult females and males' longevities, there was also a significant reduction in the number of eggs laid by each female and percentages of hatchability of these eggs compared with control. The latent effect of these compounds on some biochemical parameters in larvae resulted from treated eggs was analyzed for total protein, Free-amino acid,   chitinase activity, N-acetyl- glucosamine and Phenoloxidase activity. The results showed significant reduction in all biochemical parameters but chitinase was significantly high compared with control. In general, the tested compounds had latent significant biological and biochemical effects on the pink boll worm.