This three-part article presents: (1) a review of the construct of participation; (2) an overview of the 12-item Sydney Psychosocial Reintegration Scale (SPRS) as a measure of participation and as a description of new developments resulting in its revision (SPRS-2); and (3) as an application in different neurological groups. Psychometrically, the SPRS performs very well. There are no significant floor or ceiling effects, and both Form A (change since injury) and Form B (current status) show excellent inter-rater and test–retest reliability. There is also substantial evidence for its validity (concurrent, discriminant, and convergent/divergent), and it shows good fit to a Rasch model, providing evidence for its construct validity. Rasch logit scores are used to provide reliable change index values to determine whether an individual patient's scores have improved or deteriorated. In Part 3, three samples were compared: traumatic brain injury (TBI; n = 130), primary brain tumour (PBT; n = 54), and spinal cord injury (SCI; n = 50) on the SPRS-2 Form B. The TBI sample performed more poorly than the PBT and SCI samples on the interpersonal relationships and occupational activity domains. On the living skills domain, the TBI and SCI groups both performed more poorly than the PBT sample. These data demonstrate the differential levels of participation observed in different neurological groups.