Conservation biology is a branch of ecology devoted to conserving biodiversity. Because this discipline is based on the assumption that knowledge should guide actions, it endows experts with a power that should be questioned. The work of the French philosopher Michel Foucault can be seen as a relevant conceptual resource to think these aspects of conservation biology through. I critically analyse the relevance of the Foucauldian approach to conservation. I argue that Foucauldian arguments are deeply ambiguous, and therefore useless for (...) conservation purposes, unless they are supplemented with unsaid assumptions that are, depending on the case at hand, untenable, or at least at odds with basic assumptions underlying conservation biology. In any case, the prospects of using the Foucauldian approach for conservation purposes are deeply undermined. However, the Foucauldian reasoning contains some ideas that can be important and useful for conservation purposes, if they are duly clarified. (shrink)