Conjugated linoleic acid (CLA) acts as a potent cancer inhibitor and biological modulator in several animal models by incorporation in the lipid fractions . Now we report the possibility of incorporation of dietary CLA into insect body lipids, Chemically-synthesized CLA from safflower seed oil was supplied to house fly (Musca domestica) larvae and adults with diet supplements at various levels. Amount of CLA in the pupa and adult body was proportional to the concentrations of CLA in the diet. CLA amount in pupae and adults was 0.17 mg/g and 0.41 mg/ g of body, respectively, by 0.1% CLA diet (the lowest dosage), whereas it dramatically increased to 3.05 mg/g and 1.51 mg/g of body, respectively, by 10% CLA diet(the highest dosage). The dietary CLA did not show any adverse effects on the development of larvae and pupae, survivorship and fertility of adults, and eclosion of deposited eggs.