Traumatic brain injury (TBI) can reduce people's ability to monitor their own actions and identify and correct errors on everyday tasks. This usually occurs because of damage to neural pathways that support ‘metacognition’ or the higher-order capacity to reflect upon and regulate one's own behaviour. This paper initially reviews the neuro-cognitive mechanisms underlying error self-regulation. An overview of assessment approaches is provided which emphasises how approaches to measuring error self-regulation following TBI have been extended from the laboratory to people's real life environments. Over the last few decades, the evidence base supporting the efficacy of error-based learning or metacognitive approaches in rehabilitation has advanced considerably. An overview of the theory underpinning rehabilitation approaches and evidence supporting the efficacy of error-based learning is provided. Finally, the paper briefly describes the protocol for a randomised controlled trial that aims to determine whether people with severe TBI benefit from making errors when they learn new complex tasks.