Noble crayfish (Astacus astacus L.) is one of the four native species of freshwater crayfish from family Astacidae inhabiting Croatian freshwater ecosystems. Also, A. astacus inhabits big part of the Europe. Freshwater crayfish play a key role in the proper functioning of ecosystems and nutritional networks, and it is therefore important to preserve populations throughout the Europe that are vulnerable due to regulations of water flows, contamination of fresh water, alien invasive species and diseases such as crayfish plague. It is known that organisms adapt to specific environmental conditions in different ways and that some of these adaptations can also affect the population morphology itself. The aim of this thesis is to study morphological characteristics of species and to compare populations from different regions in Croatia. For the purpose of this study, 230 individuals were collected and parts of the body of interest were measured, and then the obtained data were analyzed in statistical programs by methods of geometric morphometry. The results showed that there is a visible difference in morphometry with respect to the filogrup, the basin and the habitat to which the individuals belong. This is the first study of A. astacus geometric morphometrcs in Croatia and the results will serve in the further studies of genetic, ecological, evolutionary and taxonomic characteristics of the species.