OBJECTIVE: To describe a programme of community education and mobilization to promote uptake in a cluster-randomized trial of tuberculosis preventive therapy offered to all members of intervention clusters. SETTING AND PARTICIPANTS: Gold mines in South Africa, where tuberculosis incidence is extremely high, despite conventional control measures. All employees in intervention clusters (mine shaft and associated hostel) were invited to enrol. MAIN OUTCOME MEASURE: Cumulative enrolment in the study in intervention clusters. RESULTS: Key steps in communicating information relevant to the study included extensive consultation with key stakeholders; working with a communication company to develop a project 'brand'; developing a communication strategy tailored to each intervention site; and involving actors from a popular television comedy series to help inform communities about the study. One-to-one communications used peer educators along with study staff, and participant advisory groups facilitated two-way communication between study staff and participants. By contrast, treatment 'buddies' and text messaging to promote adherence proved less successful. Mean cumulative enrolment in the first four intervention clusters was 61.9%, increasing to 83.0% in the final four clusters. CONCLUSION: A tailored communication strategy can facilitate a high level of enrolment in a community health intervention.