Uroscopy - the diagnosis of disease by visual examination of the urine - played a very prominent role in early modern medical practice and in the lives of ordinary people. Widely considered as the most reliable way to diagnose diseases and pregnancies it was taught at the best universities. Leading physicians prided themselves on their mastery in this field. Countless medical writings were dedicated to uroscopy and artists represented it in hundreds of illustrations and paintings. Based on a wide range of textual and visual sources, such as autobiographies, court records, medical treatises...