The results of the study of the dental anthropology complexes of the population of the Sargatka, Gorokhovo and Kashino cultures of the Early Iron Age in Western Siberia are presented. The source base of the study is 490 individuals from burials located in the Tobol, Ishim, Irtysh River regions, as well as on the territory of the Baraba forest-steppe zone. The aim of this study is to reconstruct the origin and processes of the formation of the anthropological composition of the population of the Sargatka, Gorokhovo and Kashino cultures on the basis of new dental anthropological data. Trigonometrically transformed dental trait frequencies were subjected to the principal component analysis. Besides Sargatka, Gorokhovo and Kashino cultures samples, 17 Bronze Age and 27 Early Iron Age dental samples from different region of Eurasia were used for statistical comparison. The results of the statistical comparison may possible to make a several conclusions. The anthropological composition of the Gorokhov population and Sargat groups from the Tobol, Ishim and Irtysh River regions was significantly influenced by diachronic contacts with the descendants of the Andronovo tribes of the Southern Urals, and synchronous relation with the Savromats and Sarmatians of the Southern Urals. The population of the Sargatka culture and the Gorokhovo groups, simultaneously living on the territory of the Tobol River region in the 5th–3rd centuries BC significantly different from each other. However, the subsequent close population relation between the Sargatka and Gorokhovo groups and their contacts with the Sarmatians contributed to the convergence of their anthropological composition. In the formation of the anthropological composition of the Sargatka population of Baraba forest-steppe zone the main role belongs to the local Late Bronze groups — the Fedorovo Bronze Age population of Western Siberia and their descendants, people of the Irmen culture. The most specific is the anthropological composition of the Kashino population. The specificity of the small group of the Abatsky 3 burial of Kashino culture from the Ishim River region lies in the sharp predominance of the features of the “eastern” dental non-metric complex, which distinguishes this population from the groups of the Bronze Age and the Early Iron Age of Western Siberia and adjacent territories.