The Seversky Donets River (Northern Donets) basin in eastern Ukraine and the Lower Don River valley in Russia were inhabited by populations that have been considered to be one of the earliest pottery-using cultures in Europe. The early pottery sites are all located on riverbanks and contain middens with many mollusk shells and fish bones. This suggests the intense exploitation of freshwater resources. The accuracy of radiocarbon dates obtained from these locations is of crucial importance for understanding the development of new technologies, diversification of the food consumed and its preparation strategies, as well as the degree of sedentism in this region, associated with the beginnings of pottery-making technology. The chronology of Neolithic sites in this region, however, was developed on the basis of 14C dates commonly obtained through the dating of freshwater mollusk shells, pottery with mollusk shell temper, or organic residue on pottery shards. Such samples are potentially affected by the freshwater reservoir effect, raising concerns about the accuracy of those dates. This paper presents accelerator mass spectrometry (AMS) 14C dates from a small pilot study from sites in eastern Ukraine in order to test for the presence of the reservoir effect in this region. The AMS 14C dates presented in this paper challenge the 14C chronology based on mollusk shell or organic residue, which appears to generate much older dates than those on wood charcoal or terrestrial animal bone.