Skull characters of wild boars (Sus scrofa L.) from four regions of Bulgaria were compared using stepwise discriminant, cluster of cases and principal component analyses (PCA). Classification functions were derived for discriminating individuals from different areas. Specimens from the north-eastern part of the country (Dobrudja and the Balkan Range) were found well separated from those from the south (Rila-Rhodopes & Strandja Mountains). PCA showed the differences being mostly related to the size rather than to the shape of both the cranium and the mandible. Natural migrations, intergradation areas between different subspecies, as well as restocking and hybridization with semi-domestic pigs are discussed as possible factors influencing the solution of the problem of the intraspecific systematics of the wild boar in Bulgaria.