The effects of some compounds (diflubenzuron, lambda-cyhalothrin and profenofos) were tested against 2nd and 4th instars larvae of cotton leafworm. The obtained LC50's were 0.26, 1.38 and 2.65 ppm against 2nd instar larvae. While, it gave 11.39, 12.44 and 14.40 ppm in case of the 4th instar larvae. Also, the effects of B. thuringiensis and lettuce oil extract were tested against the 2nd instar larvae showing LC50's of 1.93 x 104 ppm and 3.64 x 104 ppm, respectively. Addition of lettuce oil extract to profenofos increased the percentage mortality which were (86.6% or 73.3%) for LC50 or LC25, respectively. When lambda-cyhalothrin was mixed with lettuce oil extract it showed an antagonistic effect. The mortality percentages were (26.6% or 8.3%) with LC50 or LC25, respectively. The LC50 of lettuce oil extract was mixed for 48 hours with (LC50 or LC25) of B. thuringiensis or with diflubenzuron. The obtained results showed an increase in the mortality percent recorded after 48 hours of treatment in comparison with control. The obtained percentages of increase were (83.3% or 66.6%) for B. thuringiensis and (80% or 65%) for diflubenzuron, respectively.