Starting from a qualitative research concerning the management of the secret of the HIV among immigrant women from sub-Saharan origins living in Switzerland, this article focuses on the methodological and ethical issues requested from such kind of survey. The notions of posture, commitment and participation are here explored. In order to illustrate the ethical dimensions and methodological difficulties, the article is organized in two parts. The first one analyses the institutional constraints due to the research in a public hospital. The second one concerns the political dimension during the delicate stage of the results’ feedback and its impact on women life. Here, the notion of participation in the production of scientific (sociological) data shows the emergence of the concept of scientific citizenship.