 The lack of consistency in outcome measurement within the field of acquired brain injury (ABI) leads to incomparability of collected data and, consequently, reduced generalisation of findings. We aim to develop a set of standardised measures which can be used to obtain the minimum amount of data necessary to characterise ABI-patients across all healthcare sectors and disciplines and in every stage of recovery; i.e., an ABI-specific minimal dataset (MDS-ABI). The current study was conducted to identify the core outcome domains for adults with ABI (what to measure?) and to select the most suitable measurements within these domains (how to measure it?).