The virtually universal theme of transsexualism, the idea that a person can or should under certain circumstances change his or her original sex has had a particularly long, complex, and productive history in South Asia. From the time of the earliest known Sanskrit texts through the biographies of medieval and modern religious and political leaders, to contemporary fiction this theme has been closely connected with some of the region's most central theological, aesthetic, and social ideologies. In this study I will survey and discuss a number of salient examples of transsexualism drawn from the religious and mythological texts of ancient and medieval India. I will also discuss some signficant manifestations of the theme in cultic practices at various shrines in north and south India, and in the lives and teachings of several important modern Indian religious figures and members of organized religious communities. In doing so I will propose an analysis of the theme and its role in the constructions of gender, power, and authority in a traditional patriarchal society.