Abstract Background. Self-management and self-efficacy for physical activity is not routinely considered in neurologic rehabilitation. Objective. This study assessed feasibility and outcomes of a 14-week physical activity self-management and coaching intervention compared with social contact in Huntington disease (HD) to inform the design of a future full-scale trial. Design. Assessor blind, multisite, randomized pilot feasibility trial. Setting. Participants were recruited and assessed at baseline, 16 weeks following randomization, and then again at 26 weeks in HD specialist clinics with intervention delivery by trained coaches in the participants’ homes. Patients and Intervention. People with HD were allocated to the ENGAGE-HD physical activity coaching intervention or a social interaction intervention. Measurements. Eligibility, recruitment, retention, and intervention participation were determined at 16 weeks. Other outcomes of interest included measures of mobility, self-efficacy, physical activity, and disease-specific measures of motor and cognition. Fidelity and costs for both the physical activity and social comparator interventions were established. Results. Forty percent (n = 46) of eligible patients were enrolled; 22 were randomized to the physical intervention and 24 to social intervention. Retention rates in the physical intervention and social intervention were 77% and 92%, respectively. Minimum participation criteria were achieved by 82% of participants in the physical intervention and 100% in the social intervention. There was no indication of between-group treatment effects on function; however, increases in self-efficacy for exercise and self-reported levels of physical activity in the physical intervention lend support to our predefined intervention logic model. Limitations. The use of self-report measures may have introduced bias. Conclusions. An HD physical activity self-management and coaching intervention is feasible and worthy of further investigation.