Abstract We examined degree of between-sides difference in number of femoral pores (fluctuating asymmetry, FA) in Podarcis muralis populations, distributed on islands and in coastal area of Lake Skadar (Southern Montenegro). The aim of this study was to test sensitivity of fluctuating asymmetry of chosen trait to isolation effect in the absence of anthropogenic impacts. The results indicate that FA in the number of femoral pores do not vary significantly between insular populations of P. muralis. Generally, there is negative but non-significant correlation between island size and FA level. Also, overdominance hypothesis of enhanced developmental homeostasis at higher levels of heterozygosity was not confirmed in this study. The results support earlier conclusions obtained from electrophoretic studies, that analyzed insular populations from Lake Skadar archipelago still do not suffer deleterious effects as a result of isolation.