This article addresses the linguistic evidence from which details about Philippine “negritos” can be inferred. This evidence comes from the naming practices of both negrito and non-negrito peoples, from which it can be inferred that many negrito groups have maintained a unique identity distinct from other groups since the dispersal of Malayo-Polynesian languages. Other names, such as Dupaningan and Dumagat, reference locations, from which it is assumed the negritos left after contact with Malayo-Polynesian people. Evidence also comes from the relative positions of negrito groups vis-à-vis other groups within the subfamily with which their current language can be grouped. Many of these languages can be shown to be first order branches, suggesting early separation from the people whose languages they first acquired. The geospatial distribution of the northern languages of the Philippines closely matches the proposed dispersal routes of early Malayo-Polynesian peoples into the Cagayan River Valley and up the Chico and Magat tributaries from which negrito groups were displaced. One lexical item that is discussed is the word for the traditionally widespread practice of head-hunting, the term for which is reconstructible to Proto-Austronesian with reflexes throughout the Philippines and countries to the south. The practice was probably associated with agriculture and not only may have contributed to the early rapid spread south of Malayo-Polynesian languages through the Philippines and ultimately into the Pacific but also was later a major factor in the long periods of isolation of negrito peoples, during which the languages they had first acquired became very different from that of their former neighbors.