After the prolonged (about 30 years) absence of Crimean-Congo hemorrhagic fever (CCHF) morbidity in the Stavropol territory cases of this infection were registered, and received laboratory confirmation, in summer of 1999-2000. At the end of the 1999 season antibodies to CCHF virus were detected among cattle-breeders in all 7 inspected regions of the territory. According to the data of the determination of virus contamination of Ixodes ticks (the season of 2000), the circulation of CCHF on the territory of 14 regions out of 24 expected was established. An essential factor of the exacerbation of the epidemic situation was a rise in the number of Hyalomma marginatum ticks, the main vector of the causative agent of CCHF in the south of Russia.