A serological survey of 440 sera in order to demonstrate antibodies against the following arboviruses : Chinkungunya, O'Nyong-Nyong, Yellow fever, Zika, Uganda S, West Nile and Bunyamwera, showed that 91% of these sera contained antibodies against one at least of these viruses. In the A group, 55.1 % of the sera contained antibodies against Chikungunya virus. In the B group, 86.7 % of the sera contained anti-amaril antibodies; however, a restriction should be made: since 1939, the population of Senegal is subjected to anti- yellow fever systematic vaccinations.