Chromatographic fractions of Himalayan cedarwood oil (Cedrus deodara) were bioassayed against the pulse beetle (Callosobruchus analis F.) and the housefly (Musca domestica L.). Almost all fractions showed insecticidal activity against both test species. Fractions I and V led to the highest mortality and also produced a quick knockdown effect. Fractions I and V, after rechromatography and purification, yielded himachalol (3%) and β-himachalene (31%), based on essential oil weight, respectively. Further evaluation of these two naturally occurring sesquiterpenes indicated 97.5% mortality at 0.56 μmol/insect against the pulse beetle. These biologically active natural products of plant origin may serve as a suitable prototypes for development of commercial insecticides.