This article is the first to explore Norwegian HIV/AIDS policy and activism. Drawing on a range of archival material and oral history interviews, it does this along two lines. First, it analyses how AIDS unfolded in the changing political landscape and health bureaucracy of the 1970s and 1980s. The question is addressed of how AIDS challenged and shaped social medicine, an important ‘thought style’ of the postwar health bureaucracy and an important factor in the creation of the welfare state. Second, the article contributes to a growing AIDS historiography tracing the genealogy of AIDS activism in gay and lesbian health activism in the preceding decades. At the advent of AIDS, formal and informal networks already existed between gay and lesbian communities, activist organisations and the authorities. The roles of gay and lesbian medical professionals and activists are traced, together with how they challenged paternalistic and heteronormative notions of social medicine and homophobic attitudes in the public healthcare system. By having one foot in the medico-political world and one in the queer communities, they were able to mediate and translate different kinds of expertise and knowledge to the authorities, the public and the affected communities. This ‘amphibious’ role gave them credibility with both the authorities and the communities when addressing public health issues and preventive work. However, this story demonstrates that gay AIDS activists were not immune to the reproduction of exclusionary or hierarchical mechanisms within the queer communities. It shows how the juggling of different roles sometimes posed difficult dilemmas for the activists and how challenging but important this amphibiousness was to them.