Two cases of thickening of the internal tables of the frontal bones (hyperostosis frontalis interna, (HFI)) have been examined. These were two female skeletons from the 16th century Dominican Church in Raciborz (Southwest Poland). The similarity of their morphological and metrical traits indicates that they could be related, and suggests that HFI is likely to have a genetic base. These two skeletons are the subject of an analysis which may possibly throw some new light on the controversial and continually disputed nature of this illness.