The Eurasian lynx (Lynx lynx) and the European wildcat (Felis silvestris) are the only representatives of the cat family that live permanently on the territory of the Republic of Croatia. Although they are in the same family, they differ significantly in morphology and ecology and they are in predator – prey relation. As part of the "LIFE Lynx" project, camera traps were set in the Gorski Kotar area for the purpose of monitoring the Eurasian lynx (Lynx Lynx). They were placed in targeted marking sites which, in addition to the Eurasian lynx (Lynx lynx), proved to be interesting for numerous species of animals, including the European wildcat (Felis silvestris). Activity analysis of these two species based on the collected data obtained through camera traps was conducted. Differences in their seasonal, monthly and daily rhythm dynamcs were analysed, as well as infulence of reproduction period on the activity of these two species at the marking sites. Length of visits was recorded as well ase behavior of animals and the effort was made to study the influence of presence of Eurasian lynx (Lynx lynx) as a predator on the activity of the European wildcat (Felis silvestris). Considering that both species are nocturnal animals and reproduce in the similar period of the year, it turned out that their activity period differs more than expected what can be ascribed to wildcat's avoidance of predation.