The accidental discovery (in 1951) of two human skeletons in a gravel quarry in the absence of any accompanying artifacts, was dated to the Paleolithic on the basis of geological examination. The samples including a skull of a man aged approximately 30, featuring a trepanation hole were radiocarbon dated by the Gliwice and the Poznan Laboratories as follows: 3350±370 BP, 2700-700 BC and 4080±35 BP, 2860-2490 BC and indicate that the human remains come from the Late Neolithic, or possibly even from the Bronze Age. Owing to the present research the authors believe that any reports of the existence of signs of healing should be rejected categorically and that for several reasons, which show unequivocally that the individual must have passed away during the operation or his survival time was not long enough for any of the processes to take place; taking into account clinical data, it would not have been more than several days. Worth noting is the method by which the trepanation was performed (extent of the hole, fair regularity of the edges), suggesting some relevant knowledge and skill of the 'surgeon'. The 'advanced' technique of the operation, as well as the size of the hole constitute yet another argument against an earlier dating of the skull. The known cases of pre-Neolithic trepanation are characterized by smaller dimensions and use of simpler methods, such as drilling or scraping. The oldest cases of trepanation in Polish territory should now be dated, as in the rest of Europe, to the Neolithic. In the light of the studies of the skulls from Ukraine (Vasiljevka II and III) and Portugal (Concheiro da Moita de Sebastiao), is proved that trepanation was known in this continent in the Mesolithic. 2 Figures.