Recently collected evidence shows the likely existence of twelve South American Indian languages with object-initial word order. This is contrary to what had been generally predicted in the literature on word order typology before 1977. Numerous examples are provided of OVS (Object-Verb-Subject) and OSV (Object-Subject-Verb) word order, primarily from the Carib languages. The constituents of these sentences and their positions are discussed in detail. In addressing the question of where these object-initial languages come from diachronically, it is suggested that a number of the OVS Carib languages represent breakaways from OVS languages of the area which exists today. This word order change is based on the grammaticalization of an older stylistic but frequently used option of subject postposing. The areal clustering of these languages is not due to either the genetic relatedness of the languages concerned or to contact between the languages; the languages discussed fall into five different families, and there is no evidence of contact between them. (PMJ)