The article aims to discuss the sociological attributions of Sarmatian cultural groups referred to in written sources as epsilon theta voc gamma epsilon voc (in Greek) and natio, gens (in Latin). These terms are the legacy of two potestary structures, namely the tribe and the chiefdom. Archaeological evidence makes it possible to reconstruct local groupings of burial mounds dating back to the Sarmatian period and to describe Sarmatian tribal communities in terms of potestary structures. This article seeks to focus on the concept of the tribe, its meaning and its functions. The tribe is then compared to the chiefdom, with structural and functional differences between the two concepts being viewed as quite substantial. The concept of a 'Sarmatian tribe' is legitimate and expedient enough to apply to decentralized nomadic communities, whose material culture does not reflect the criteria of chiefdom.