Sera from patients with acute seasonal fevers and apparently healthy individuals living in the Astrakhan Region, Krasnodar Territory, or Rostov Region were examined in two modifications of enzyme immunoassay for detection of IgM and IgG antibodies to Neapolitan and Sicilian pappataci fever viruses. IgM antibodies to Sicilian pappataci fever virus were detected in a patient from the Volodarsky District, Astrakhan Region, who had been admitted for the unverified diagnosis of Q fever. A donor residing in the Novorossiysk District, Krasnodar Territory, was found to have IgA antibodies to Neapolitan pappataci fever virus. The findings show it expedient to conduct further investigations of the serodiagnosis and seroepidemiology of pappataci fevers in the southern Russian region where mosquitoes of the genus Phlebotomus inhabit.