Byline: Lenore Hawley, Research Department, Craig Hospital, Englewood, Colorado (Mss Hawley and Morey, Mr Sevigny, and Drs Ketchum, Harrison-Felix, and Tefertiller); and John Walsh Centre for Rehabilitation Research, Sydney School of Medicine, The University of Sydney, Sydney, New South Wales, Australia (Dr Simpson).; Clare Morey; Mitch Sevigny; Jessica Ketchum; Grahame Simpson; Cynthia Harrison-Felix; Candace Tefertiller Abstract OBJECTIVE: To evaluate the efficacy of a novel intervention aimed at enhancing self-advocacy in individuals living with traumatic brain injury (TBI). SETTING: Community. PARTICIPANTS: Sixty-seven (35 allocated to treatment, 32 to control) community-dwelling adults 9 months or more post-TBI (mean of 8.9 years postinjury); previously discharged from inpatient or outpatient TBI rehabilitation; able to travel independently in the community, indicating a level of independence needed to engage in self-advocacy. DESIGN: Longitudinal randomized 2-arm controlled trial (NCT no. 03385824). Computer-generated block randomization allocated participants to treatment/intervention or control/no-intervention. All outcome assessments completed by blinded study staff. INTERVENTION: A manualized group intervention, Self-Advocacy for Independent Life (SAIL), addressing the self-efficacy beliefs, knowledge, and skills for self-advocacy following TBI. MAIN OUTCOME MEASURES: The Self-Advocacy Scale (SAS) (primary); General Self-Efficacy Scale (GSE); Personal Advocacy Activity Scale (PAAS); Satisfaction With Life Scale (SWLS). RESULTS: The treatment group showed significantly greater improvement than controls from baseline to posttreatment on the primary measure (SAS) of self-efficacy specific to self-advocacy after TBI (effect size = 0.22). Similar improvements were found on secondary measures of general self-efficacy and satisfaction with life from baseline to posttreatment. However, significant between-groups gains for primary and secondary measures were not maintained over 6- and 12-week follow-up. CONCLUSIONS: Individuals living with chronic TBI sequelae can increase self-efficacy specific to self-advocacy, general self-efficacy, and satisfaction with life, through a TBI-specific intervention aimed at empowering individuals to advocate for their own needs and wishes. Sustaining gains over time may require ongoing community collaboration and support. This could involve community-based systems of self-advocacy education, resources, and peer support.