The mortality rates od Aedes togai mosquito either uninfected or infected with Brugia pahangi maintained in insectary for 12 days with various concentrations of the combined pyrimethamine (P) and sulphadoxine (S) in 10% sugar-water solution: 5 mg% P+100mg%, 10mg%P+200mg%S, and 20%P+400mg%S significantly increased compared cto that of the control groups. The present evidence showed a deginite insecticidal action of the combined drugs. Infection and infective rates of Ae. togoi mosquitos, average number of B. pahangi larve and infective larvae per infected mosquitores, average size and movement of the larvae in the groups of mosquitoes treated with various concentrations of the combined drugs for 12 days decreased significantly compared to that of the control groups of mosquitoes. The present evidence demonstrated a deginite action of the combined pyrimethamine and sulphadoxine as an antifilarial in B. pahangi-Ae togai model infection.Keywords:pyrimethamin-sulphadoxine-Brugiapahang-Aedes togai-antifilarial-insecticide. Sugeng J. Mardihusodo