Background: Groups are an integral part of everyday life. Some groups are chosen by participants whereas membership in other groups may not be an active choice.The benefits of participation in groups are widely documented, and perhaps most commonly cited are Yalom's eleven curative factors of group therapy, examples of which include the instillation of hope and imparting of knowledge. Groups have long been used therapeutically and are increasingly used as a context for delivery of rehabilitation interventions. Following a traumatic brain injury (TBI), rehabilitation is recommended to maximise recovery and the use of groups in TBI rehabilitation programmes is common practice, particularly in occupational therapy. TBI results in a complex variety of impairments that can interfere with an individual's ability to participate in their life roles and activities. Therefore, groups in TBI rehabilitation may pose some unique challenges for facilitators. Currently there is limited research evidence to guide clinicians in the facilitation of groups with this population group. In addition, there is limited literature investigating key stakeholder's perspectives of group participation in TBI rehabilitation. The purpose of this thesis is to explore processes and perspectives of participation in inpatient occupational therapy groups in TBI rehabilitation.Objectives: The aims were 1) to scope the current state of evidence regarding the use of groups in rehabilitation following TBI; 2) to explore the perspectives of patients with TBI about participation in inpatient occupational therapy groups; 3) to investigate the perspectives of clinicians from multiple rehabilitation settings about facilitation of groups with patients following TBI; and 4) to explore the nature of interactions in inpatient occupational therapy groups in TBI rehabilitation.Method: A mixed methods approach was used. The primary components of the thesis were a scoping review, focus groups with clinician participants, questionnaires and individual interviews with patient participants, and video-recordings of inpatient occupational therapy groups. A total of 46 rehabilitation inpatients recruited from the occupational therapy groups programme at the hospital participated in the study, with fifteen completing individual interviews. Twenty-two clinicians and four student iii clinicians who worked in inpatient occupational therapy teams in brain injury, spinal cord injury and geriatric rehabilitation settings from one hospital participated in the study. The thesis explored the experiences and perspectives of participants and was guided by a phenomenological approach. The method of qualitative analysis for focus groups was framework analysis. Thematic content analysis was utilised to analyse interview data. Descriptive statistics were used to analyse questionnaire data. Qualitative analysis guided by qualitative description was used to analyse video data.Results: The scoping review concluded that existing research about the use of groups in TBI rehabilitation consiste...