We present the application of computed tomography (CT) and scanning electron microscope (SEM) technologies for the analysis of the Mesolithic skull of an adult individual from Wieliszew (Poland; ca. 5850 BC). Macroscopic examinations carried out in the 1950s showed a bone defect on the skull identified as post‐mortem. On this basis, it was argued to be evidence of cannibalistic practices in the Mesolithic period. CT and SEM demonstrated that the transverse fracture in the frontal squama has regular, oblique, sloping margins. Close to the right end of the fracture, features of healing were identified. It suggests that the individual survived the insult, at least till the beginning of the early reparative phase. It is the first time a documented case of violence has been detected in the Mesolithic in Poland. The applied CT and SEM technologies showed that the previous interpretation of the wound on the skull of Wieliszew as a trace of cannibalistic practice turned out to be wrong.