We applied capture-mark-recapture (CMR) methods to estimate the population size of the Tavas frog Rana tavasensis in its terra typica. For this purpose, we used Pollock?s robust design in program MARK in the 2011-2015 breeding seasons in its terra typica. Based on the selected model, equal catchability of each individual and absence of temporary migration were found to be the most likely biological hypotheses. Population sizes were estimated as 398, 348, 275, and 117 individuals during the four study years, respectively. Annual capture probabilities were estimated to average 0.07, and annual survival rates across years averaged 0.19. The year-specific estimations showed a remarkable decline in population size and survival rates. Anthropogenic factors, such as off-road activities, recreational activities, and animal grazing, might have played a role in this decline. This trend provides us with useful knowledge for conservation and management activities.