This article presents the findings of a study of selected religious and secular non-governmental organisations (NGOs) working on HIV/AIDS in Nigeria. The study sought to identify whether, and in what circumstances, so-called faith-based organisations (FBOs) have distinctive characteristics with respect to their goals, values, organisational characteristics, and activities, compared to secular NGOs. It found that the FBOs studied are perceived by their staff, beneficiaries, and local observers as possessing some distinctive features and comparative advantages relative to secular NGOs.