Hydrolytic enzymes like chitinase are key factors in entomopathogenic fungi infections of insects. Chitinolytic activity of Lecanicillium lecanii was detected when growing in chitin and in grasshopper cuticle (Sphenarium purpurascens) in solid-state fermentation (SSF); the highest levels were reached when the fungus grew in chitin. Expression levels of chitII gene in L. lecanii depend on the carbon source present in the medium, and an increment in chitII gene expression was observed through fermentation time. Among the carbon sources evaluated, chitin showed the highest levels of chitII gene expression. When grown in glucose, basal levels of expression of chitII gene were detected, suggesting that the L. lecanii chitinolytic system is subject to an induction/repression mechanism. Electrophoresis in SDS-PAGE of a partially purified extract obtained from the growth on chitin and S. purpurascens cuticle revealed a band of 23 kDa approximately with β-N-acetyl-glucosaminidase activity in a zymogram analysis.