This introduction to 'Translating Sex' places the six essays included in this special section in the context of the history of sexuality in the Indian subcontinent, and argues for a need to write more comprehensive histories of sexology-the field of inquiry which promoted the understanding of sex as a 'scientific object' around the globe at the turn of the twentieth century. It identifies the divergent materials covered in, and the common grounds occupied by, the six essays that deal with sex as a translated object of knowledge; considers the history of vernacular sexology; and showcases the ubiquity of sexology in socio-cultural, political and literary debates in the Indian subcontinent in the first half of the twentieth century. It argues that by locating sexology in Indian history, we can render 'sexuality' a more useful category of analysis for this context as well as comprehend what might be termed the sexuality of Indian history.