Plio-Pleistocene suid assemblages of sub-Saharan Africa seem to have been derived from the immigration of Asian tetraconodontines during the late Miocene and of Asian suines in the mid Pliocene. Lineages of both subfamilies display evolutionary changes that decrease the length of the premolar row and increase the length, height and complexity of the molars. Such changes have proved useful for estimating the relative ages of the sites from which suid fossils have been retrieved. They have also been used for interpreting the probable habitat and as evidence of environmental change through time. Isotopic analyses of tooth enamel from extant suid species generally confirm field observations of their dietary preferences. Similar analyses of suid dental enamel from Neogene localities of eastern Africa provide information that partly supports previous interpretations of the diets of extinct suid species. The increase in size and complexity of nyanzachoere teeth reflects their exploitation of C4 vegetation, although the nyanzachoeres did not acquire their grazing habits until after contemporary perissodactyls and proboscideans had become dedicated C4 grazers. In contrast to earlier interpretations, kolpochoeres and metridiochoeres were already dedicated grazers by the time they became significant components of the East African biota. Like their living counterparts, the warthogs and forest hogs, metridiochoeres were less water-dependent than kolpochoeres.