This paper represents the early beginnings of a new research project examining Catholic women religious (sisters and nuns) and HIV/AIDS ministries in Britain in the 1980s-2000s. It asks why and how they mobilized around HIV/AIDS. First, it identifies the variety of HIV/AIDS ministries: most sisters worked as chaplains (typically employed in state-run hospitals) or as volunteers in charitable organisations (that were typically Christian or secular) rather than in the Catholic health care sphere. Second, it addresses their motivations in selecting particularly HIV/AIDS ministries that provided social care to people with HIV/AIDS and considers the tensions and synergies between compassion and social justice. Lastly, it examines the response of the Hierarchy of England and Wales to sisters' activism to identify how the Church's moral stance with regards to homosexuality and HIV/AIDS influenced their ministries.