Lasting socio-emotional behaviour difficulties are common among children who have suffered brain injuries. A proportion of difficulties may be attributed to impaired cognitive and/or executive skills after injury. A recent and rapidly accruing body of literature indicates that deficits in recognizing and responding to the emotions of others are also common. Little is known about the development of these skills after brain injury. In this paper we summarize emotion-processing systems, and review the development of these systems across the span of childhood and adolescence. We describe critical phases in the development of emotion recognition skills and the potential for delayed effects after brain injury in earlier childhood. We argue that it is important to identify the specific nature of deficits in reading and responding to emotions after brain injury, so that assessments and early intervention strategies can be devised.