The extensive use of insecticides in public health and agriculture sectors is the main reason for development of resistance in fleas associated in domestic rodents. The present work was planned to investigate the insecticidal efficacy of Lambda-cyhalothrin, Chlorpyrifos and Fenitrothion against rat flea (Xenopsylla cheopis) infesting rodent species in Giza Governorate, Egypt. The lethal concentration Lc50 and Lc90 of population percent were obtained from the established regression log concentrate-response lines. Data indicated that the values of lethal concentration (Lc50) were 0.293, 1.725 & 2.328 % for Lambda-cyhalothrin, chlorpyrifos and Fenitrothion, respectively. The values of lethal concentration (Lc90) were 0.467, 2.839 & 5.197% for Lambda-cyhalothrin, chlorpyrifos and Fenitrothion, respectively.