A thorough understanding of the population dynamics of a species requires a detailed comprehension of the variation in its demographic parameters, (e.g., survival, recruitment, etc.) and the factors that cause such variation. These provide the necessary information to estimate the probability of extinction of a population and ultimately of a species, key in the today's time. Here, we analyze the patterns of population dynamics (survival, recruitment, probability of capture, population growth rates, and population size) and their relationship with climatic variables of a population of Liolaemus xanthoviridis. For this purpose, we used data collected in the field between 2012 and 2022 in Bahia Isla Escondida, Chubut. Parameter estimates were carried out under the approach of capture-mark-recapture models, through the Pradel model for open populations and closed models were used to estimate population size. Survival rate varied temporally and with additive effect of sex. Average survival rate was high, although from 2020 to 2022 the survival rate has decreased considerably. Recruitment only varied as a function of sex, with males having a slightly higher rate than females. Climatic variables did not prove to be important when estimating these demographic parameters. The population size decreased by half since 2020, which is in line with the estimated growth rate. We do not know the causes of the decrease in survival, growth rate, and population size during recent years, but we infer it is associated with the loss of available habitat, specifically the decrease of coastal dunes.