AbstractThis article reveals the importance of the Renaissance pharmacy for the history of the Reformation. Focusing on the case of a Venetian apothecary and physician, Gian'Battista Gemma (1537–1608), the article highlights the role of Venetian pharmacies as sites of religious and scientific innovation, as well as healthcare provision and poor relief. It argues that a pharmacy was one of the most conspicuous and radical centres for unorthodox belief in Renaissance Venice. Drawing on recent studies of medical networks, spaces and identities, and questions related to cultural transfers, the article examines the way in which contemporary apothecaries and physicians integrated their religious pursuits into their professional activities. Like contemporary preachers, schoolmasters and master printers, Venetian men of medicine emerge as a particularly energetic group of cultural brokers who were able to give their reforming ideas broad influence through a variety of social, economic and professional means.