BACKGROUND: Stroke disproportionately kills and disables ethnic minority seniors. Up to 30 % of ischemic strokes in the U.S. can be attributed to physical inactivity, yet most Americans, especially older racial/ethnic minorities, fail to participate in regular physical activity. We are conducting a randomized controlled trial (RCT) to test a culturally-tailored community-based walking intervention designed to reduce stroke risk by increasing physical activity among African American, Latino, Chinese, and Korean seniors with hypertension. We hypothesize that the intervention will yield meaningful changes in seniors' walking levels and stroke risk with feasibility to sustain and scale up across the aging services network. METHODS/DESIGN: In this randomized single-blind wait-list control study, high-risk ethnic minority seniors are enrolled at senior centers, complete baseline data collection, and are randomly assigned to receive the intervention "Worth the Walk" immediately (N = 120, intervention group) or in 90 days upon completion of follow-up data collection (N = 120, control group). Trained case managers employed by the senior centers implement hour-long intervention sessions twice weekly for four consecutive weeks to the intervention group. Research staff blinded to participants' group assignment collect outcome data from both intervention and wait-list control participants 1 and 3-months after baseline data collection. Primary outcome measures are mean steps/day over 7 days, stroke knowledge, and self-efficacy for reducing stroke risk. Secondary and exploratory outcome measures include selected biological markers of health, healthcare seeking, and health-related quality of life. Outcomes will be compared between the two groups using standard analytic methods for randomized trials. We will conduct a formal process evaluation to assess barriers and facilitators to successful integration of Worth the Walk into the aging services network and to calculate estimated costs to sustain and scale up the intervention. Data collection is scheduled to be completed in December 2016. DISCUSSION: If this RCT demonstrates superior improvements in physical activity and stroke knowledge in the intervention group compared to the control group and is found to be sustainable and scalable, Worth the Walk could serve as a primary stroke prevention model for racial/ethnic communities across the nation. TRIAL REGISTRATION: ClinicalTrials.gov NCT02181062 ; registered on June 30, 2014.