In this article we study knowledge about HIV/AIDS in Ghana. We investigate inhabitants’ medical literacy, focusing on potential misconceptions of transmission mechanisms of the epidemic. Our basic premise is that well-organized health programmes over a longer time span will better prepare and fine-tune the local mentality for scientifically founded messages. We argue that the large-scale Navrongo Project and similar activities in the upper regions of Ghana are likely to have laid the groundwork for a receptive population, when it comes to understanding and believing in science-based information. Especially, we hypothesize that people living in the Upper East Region where the Navrongo Project has been located, to be more scientifically literate and have beliefs consistent with the medical paradigm for virus transmission. The main data source for statistical analyses is the Ghana Demographic and Health Survey from 2003, with a sample size of over 10,000 respondents of both sexes, aged 15—49 years. To evaluate individual and regional differences in such AIDS beliefs, we apply step-wise multiple regression analysis. This approach allows for investigating individual influences and structural effects together, tracing regional variations, as specific control variables are added to the exploratory framework. The findings suggest that large-scale intervention programmes for improving health standards in an African context can have important long-term effects on inhabitants’ beliefs, beyond original aims. Notably, the massive Navrongo projects and related activities especially in the Upper East Region of Ghana, seemingly have increased inhabitants’ trust in the medical model as compared to alternative paradigms. The empirical pattern is at least consistent with our main theoretical arguments, although further research is needed for a stronger test