The pink bollworm, Pectinophora gossypiella, (Saunders) (Lepidoptera: Gelechiidae) considers as one of the world's most invasive insects, is a voracious lepidopteran pest of cotton. To control this insect pest and increase crop yield, chemical pesticides was mainly used and that caused resistant population and side effects for human and environment. Therefore, there is a need to increase of alternative methods such as the biological control. During the current study, five fungi isolates, one of Beauveria bassiana (AUMC 9896) and four of Metarhizium anisopliae (M1, M2, M3 &M4) were evaluated against the eggs, new hatched larvae, and pupa of P. gossypiella under laboratory conditions. Bioassay was performed using spores suspension concentrations (1.0 × 106, 1.0× 107 and 1.0×108 spores /ml). Results showed that B. bassiana (AUMC 9896) proved to be more toxicity than M. anisopliae isolates as depicted by the calculated LC50 values on all treated stages, egg, larva, and pupa. On the other hand, the highest egg and pupal mortality percentages were recorded to B. bassiana (76.7 and 80%), respectively, at the same concentration (1×108 spores /ml). Whereas the isolate M. anisopliae (M4) showed the least one (23.3, 46.6 %). Also, M. anisopliae isolates (M1 & M4) had the highest value of larval mortality (86.7%) than B. bassiana (AUMC 9896) was (66.7 %) larval mortality percentage. Thus, it can be concluded that the isolates B. bassiana (AUMC 9896 & M1) were strong pathogenicity while the isolates (M3&M4) were moderate and (M2) was showed low pathogenicity.