Archaeological investigations undertaken in the upper Gundar Basin (Madurai district, Tamil Nadu, India) between 1991 and 1996 have yielded evidence for the Mesolithic and Iron Age–Early Historic periods. The research has revealed that microlith-using hunter-gatherers continued to exist during the Iron Age and Early Historic periods, and interacted with agropastoral groups. This paper discusses the settlement system of Mesolithic hunter-gatherers and interactions between the hunter-gatherers and the agropastoral groups of the Iron Age–Early Historic period.