This chapter outlines the formal parameters of prostitution and its historical development in Spain. It deals with some of the most potent regulators of prostitution, regulators that have shaped the institution to a considerable extent and have been formally recorded within the disciplines of law, medicine and theology. The chapter discusses how the criminality or non-criminality of prostitute women has been a recurrent theme. Perhaps more than any other area of Spanish sexualities studies, the subject of prostitution has merited considerable attention from various disciplines, from feminism to theology arid from psychology to sociology. Michel Foucault's argument concerning the 19th-century construction of particular sexual identities, including that of 'the prostitute', is illuminating when applied to prostitution in Spain. The history of the legal status of prostitution in Spain is closely linked to the country's political history. Instances of punishment for women who worked as sex workers and for men who lived from sex workers' earnings have been recorded.