In this article the evidence of pig exploitation in the prehistory of the Italian peninsula and Sicily is presented. Though some differences in pig morphology seem to have existed between different parts of the country, a broadly consistent diachronic pattern of change has emerged. In the Mesolithic fairly small wild boars (with bones quite large in relation to the teeth) lived in Italy. For most of the Neolithic pigs of a similar size and shape could be found across the peninsula but signs that a few changes in systems of pig exploitation had started occurring can be found at several sites. This is interpreted as most probably indicating the beginning of a slow and gradual process of domestication of local animals. The hypothesis that early and middle Neolithic pig husbandry relied mainly on imported animals can be fairly confidently refuted. Sometime during the late Neolithic and/or the early Bronze Age, practices of pig husbandry seem to have changed throughout the country, and a much clearer separation appears between the wild and domestic populations. The average size of domestic pigs decreased, probably as a consequence of a closer confinement of domestic herds, but wild boar size seems to have increased, possibly as a consequence of climatic change or of a release in hunting pressure. Recent Italian wild boars (of the traditional Maremman type) are, however, as small as their Mesolithic counterparts, a possible indication that habitat fragmentation caused by human demographic pressure brought about a further change in wild boar size.