The main goal of this article is to analyse the relationship between reflexivity and action along three axes.The first entails the discussion of a reflexive action model that explores the combination of factors, processes and mechanisms which explain the guiding role reflexivity can play with regard to practices, in specific circumstances. The second axis concerns situations in which reflexivity does not act as an orientation mechanism and may even have the opposite effect, as a source of disorientation and paralysis of practices. The third relates to the production of social change and reproduction that may arise from the exercise of reflexivity. The whole discussion points to the mediation role that reflexivity assumes in the relationship between structure and agency, i.e. in the way structural enablements and constraints are received, filtered and mobilised by subjects in the subjective definition and reflexive implementation of their personal projects.