Cutaneous leishmaniasis (CL) patients were reported from the Hambantota district, Sri Lanka. Causative organism of CL is Leishmania donovani and the potential vector is Phlebotomus argentipes. Current study was designed to identify the potential vectors in CL infected sites in the Hambantota district, Sri Lanka. Ten households of CL positive patients were selected and dipterans were captured using the CDC light, sticky traps. Sampling of dipterans was continued one night per month from January, 2016 to January, 2017. Collected insects were preserved in 70% Ethanol. Preserved insects were identified using taxonomic keys and mounted heads and genitalia of sand flies were used for morphological identification. Student t-test and principal component analysis were used to identify the different morphological characters. Blood sucking dipterans such as biting midges (n=358) and sand flies (n=120) were captured. Phlebotomus argentipes, P.salehi and P.stantoni and Sergentomyia species such as S. babu, S. clydei, S. indica, S.punjabensis and S.zeylanica were identified. Findings indicated that some morphological characters were statistically different in sibling species such as P.argentipes s.s., P.annandalei and P.glaucus of Phlebotomus argentipes species complex in study sites. PCA analysis also pointed out that there were different clusters for different sibling species of P.argentipes species complex collected from study sites in the Hambantota district, Sri Lanka.