The organicist metaphor of the body as a political microcosm is in line with a tradition among physicians towards involvement in matters of state. In early modern Spain this metaphor flourishes, medicine being then understood as integral to the state apparatus. Andrés Laguna, Juan Huarte de San Juan, Oliva Sabuco de Nantes, and Cristóbal Pérez de Herrera are here taken as case studies to illustrate the different forms that the engagement of physicians in the politics of early modern Spain could take. It will be seen how, either upon the request of political authorities or entirely unsolicited, they expressed their political views in published works addressed to the highest political figures of their time. Underlying their proposals for reform is a wish to partake in the government of the country by performing functions proper to royal counsellors.