Medical scientific societies, just like other scientific associations, are a fairly neglected object in the studies of science. Most of the published research in this area is comprised by historical studies of individual societies, by type or by geographical region. This article aims to fill this gap by presenting original research on contemporary medical societies. It seeks to characterise what are their main activities, how do they function and what relations they establish with other actors in the scientific field. It is focused on Portuguese medical societies but if seeks to draw comparisons with other national contexts whenever there is available information. The data presented was gathered as part of a project intituled SOCSCI Scientific Societies in Contemporary Science, which aims to understand scientific societies in general. This article pays particular attention to three medical societies which were included in a sample of in-depth studies from the project: the Lisbon Society of Medical Sciences, the Portuguese Neurology Society and the Portuguese Neurosciences Society.