Mosquitoes are the important vectors of deadly diseases including Malaria, Dengue, Filariasis, etc. Malaria is caused by the malarial parasite Plasmodium falciparum. The major vectors belong to Anopheles, Aedes, Culex, and Mansonia species. These deadly vectors are commonly controlled by pesticides. But continuous use of pesticides causes resistance to develop in these vector agents. There is an urgent need to control these vector populations. Most novel alternative are semiochemicals. Semiochemicals are signaling chemicals used to carry information between living organisms, which cause changes in their behaviour. Semiochemicals are known for attractive and repellent insect activity; however, some of these also contain insecticidal properties. The Dodecanoic acid is a novel Semiochemical. It is one of the saturated fatty acid commonly found in both animal and vegetable fats and is frequently used in cosmetics, soaps, perfumes and flavorings etc. It is having the property of hypercholesterolemia among the saturated fatty acids. The Dodecanoic acid has not been fully evaluated against the malarial vector Anopheles stephensi. The present study aims to evaluate the bio-efficacy of Dodecanoic acid on larvicidal, ovicidal, pupicidal and repellent activities against the malarial vector Anopheles stephensi.