From the narrative and the analysis of a specific sequence of a research project (including anthropologists), associated with an intervention, in the field of maternal health in Senegal, this paper emphasizes the need to intertwine three levels of analysis, all of them involving the analysis of the anthropologist : an anthropology of the project as a whole to understand the logic governing its guidance, intended or sustained, and based on its characteristics or on external events ; the making of anthropology in this project ; lessons drawn from this dual position to rethink issues of anthropology in general (relation to fieldwork, construction of the object, contribution to change).