We collected and evaluated, by the ‘logarithmic size index’ (LSI) method, all available postcranial equid bones found in the Czech Republic from the Neolithic to the Early Bronze Age. Material from the Upper Paleolithic (Magdalenien) and Bohemian Late Bronze Age (Knovíz culture) was also included. Two different species of equids were documented: Equus hydruntinus Regalia, 1907 and Equus ferus Boddaert, 1785. The variation in the size of true horses was compared with data published for neighbouring countries. In most periods, the horses are found to be larger in the eastern part of Central Europe than in the western part. The Czech lands appear to span the border of two worlds: the Pannonian plains and the western, geomorphologically diverse regions. The status of horses in the Neolithic Lengyel period from Moravia remains disputable. However, a high size variability in Eneolithic Funnel Beaker culture (TRB, 3800-3350 BC) together with a non-homogeneous distribution in Řivnáč culture (3100-2800 BC) and a significant increase in size between Lengyel and Baden-Řivnáč horizons (probably already in TRB) combined with the occasional occurrence of unexpectedly large individuals probably indicate the importation of tamed or even domesticated horses as early as the times of TRB culture, which is earlier than claimed in other recent studies, and possibly reflect multiple origins of the horse population. The large variability and repeated diminution in size of horses in the Early Bronze Age (Únětice culture, 2200-1700 BC) could indicate advanced domestication or multiple origins of the populations (or both). The persistence of wild horses in the Early Bronze Age cannot be proved osteometrically, but the presence of domesticated horses is considered certain.