Objective: To enhance participation post stroke through a structured, community-based program. Design: A controlled trial with random allocation to immediate or four-month delayed entry. Setting: Eleven community sites in seven Canadian cities. Subjects: Community dwelling persons within five years of stroke onset, cognitively intact, able to toilet independently. Interventions: Evidence-based program delivered in three 12-week sessions including exercise and project-based activities, done as individuals and in groups. Main measures: Hours spent per week in meaningful activities outside of the home and Reintegration to Normal Living Index; Stroke-Specific Geriatric Depression Scale, Apathy Scale, gait speed, EuroQuol EQ-5D, and Preference-Based Stroke Index. All measures were transformed to a scale from 0 to 100. Assessments prior to randomization, after the first session at three months, six months, 12 months, and 15 months. Results: A total of 186 persons were randomized. The between-group analysis showed no disadvantage to waiting and so groups were combined and a within-person analysis was carried out at three time points. There were statistically significant increases in all study outcomes on average over all persons. Over 45% of people met or exceeded the pre-specified target of a three hour per week increase in meaningful activity and this most often took a full year of intervention to achieve. Greatest gains were in satisfaction with community integration (mean 4.78; 95% CI: 2.01 to 7.55) and stroke-specific health-related quality of life (mean 4.14; 95% CI: 2.31 to 5.97). Conclusions: Community-based programs targeting participation are feasible and effective, but stroke survivors require time to achieve meaningful gains.