AbstractPoor people tend to be vulnerable to natural hazards such as floods because of their limited resources and capacities. Community-based disaster preparedness activities aim to increase awareness of and preparedness for flood events. However, attendance often is low, and information is poorly disseminated. This study investigated effective ways to share the outcomes of community-based activities for flood risk preparedness with nonparticipant residents, including informational posters, pamphlets, and reminder letters and texts. A random sample of 152 villagers in Indonesia was sorted arbitrarily into three groups (letter reminders, text message reminders, and control). The reminders encouraged participants to view the poster. Participants completed a preintervention questionnaire prior to receiving reminders 1 time/month for 4 months. Within 2 weeks after receiving the last reminder, the participants completed a postintervention questionnaire. ANOVA, Student’s t-test (Dunnett’s test), paired t-tests, and a binary logic regression analysis tested the effects of the intervention. Results indicated that letters were effective reminders that increased knowledge of flood risk preparedness, and females were less likely than males to view the posters.