Argemone mexicana is a medicinal plant predominantly present in India. The insecticidal activity of crude extracts and different fractions of the same were investigated against Helicoverpa armigera. Pupation was the least (3.33%) in acetone extract followed by 10 per cent in the chloroform extract. Least pupal weight and maximum malformed adults were observed in chloroform extract. The adult life span was reduced in petroleum either and water extracts. Fecundity was meager in petroleum ether extract, while its solvent curtailed the hatchability. Among the acetone fractions, the first and fourth fractions resulted in nil pupation. Larval prolongation, reduced pupal weight and malformed moth emergences were also observed.