Objective: To determine spatial distribution of sand flies (Diptera: Psychodidae; Larroussius group), the vectors of visceral leishmaniasis in Ardabil province, Northwest of Iran. Methods:Sand flies were collected using sticky traps from the 30 selected points in Ardabil province, during May-November 2017. The MaxEnt model in GIS software was used for modeling. Results: A total of 2794 specimens of sand flies were collected, of which 33％ were Larroussius subgenus sand flies. Phlebotomus kandelakii and Phlebotomus wenyoni were the highest and lowest collected species respectively. Based on the modeling, four areas in the province were identified with more than 70％ probability of the presence of Larroussius group vectors which were at risk of visceral leishmaniasis disease transmission. Conclusions: The distribution of Larroussius subgenus sand flies was observed in all parts of Ardabil. But the north parts of the province (Germi and Bilesavar counties) as well as central part (Ardabil and Meshkinshahr counties) were of great importance in terms of the presence of Larroussius subgenus sand flies and the possibility of transmission of the visceral leishmaniasis.