Postglacial climatic conditions were inferred from the cores taken from two lakes in eastern Lithuania. Pollen, diatom, pigment, chemical analysis and 14 C dating were performed. Vegetation with open herb/grass predominating flourished on the unstable soils, surrounding oligotrophic palaeobasins with high water levels and low pigment concentrations that existed at about 13,200cal. The succeeding stage (13,200–12,600cal BP) indicates a formation of pine–birch woodland, rising humidity as well as biogenic productivity, and points to climatic warming. At about 12,600cal BP the re-establishment of open herb–grass–shrub communities was registered. Gradual improvement of climatic conditions started after 11,200cal BP. The period from ∼8700 to ∼6000cal BP shows an expansion of broad-leaved trees, significant increase in diatom diversity, diatom and pigment concentration, and drops in C/N ratio indicating the most favorable climatic conditions during the postglacial. After ∼4800cal BP the broad-leaved trees markedly decreased and the significance of eutrophication and human activity increased.