Synopsis The studies on Vaisnavism became pan-Indian or even world-wide. On its theology and on its spread numerous works have appeared, but there are few works, which describe the historical background of Andhra in which Vaisnavism has spread and the modifications it underwent and their significance. In this context, the Southern region i.e. Tamilnadu received attention and several studies have been published. In contrast to these studies, work on Vaisnavism in Andhra is meager. There are some standard works, which deal with certain aspects of religion confining to some dynasty or to some brief period in the history of Andhradesa. There is no independent study on the history of Vaisnavism. Hence, the present attempt which is the first of its kind. Besides presenting the historical evolution of Vaisnavism in Andhradesa, based on archaeological and literary data, it seeks to delineate its impact on the society and Telugu literature. A succinct account of prominent Vaisnava temples and mathas has also been attempted in the present study to make it as comprehensive as possible.