This article argues that the current model of resilience in the social work literature, through its predominant focus on outcomes and behaviours rather than the underlying processes of development involved, risks superficiality and appears to lack an underpinning psychological theory of the way in which resilience develops. In response I propose a psychodynamic understanding of this process, which sees resilience as rooted in the capacity for reflexivity (defined here as an awareness of one's own mental state and the mental states of others), and which describes how this capacity develops. This holds that a strong-enough ego, with the capacity for resilience-as-reflexivity, is the necessary precursor of the child's ability to make use of positive experiences. This psychodynamic understanding of resilience development aims to give social workers a greater appreciation of how the mental health of children in the care system may have been affected by their experiences, and how they can be helped to develop the psychological foundations of resilience and therefore better mental health. I suggest that workers can use this understanding to assess the stage of resilience-development a child has reached, and to inform therapeutic work aimed at strengthening their resilience.