Background: Dengue Hemorrhagic Fever (DHF) remains a major public health challenge in Indonesia, requiring effective community-based preventive strategies. Health education is considered a key intervention for improving public awareness and promoting sustainable dengue prevention practices. This study aimed to evaluate the effectiveness of a community health education program in improving knowledge regarding DHF prevention among residents in the working area of UPTD Puskesmas Mekar Sari. Methods: A community-based pre-experimental study using a one-group pre-test and post-test design was conducted among 37 community members. The intervention consisted of a 90-minute health education session delivered through lectures, interactive discussions, demonstrations, and educational leaflets emphasizing the PSN 3M Plus strategy. Participants completed identical knowledge questionnaires before and immediately after the intervention. Descriptive statistics were used to summarize changes in knowledge scores. Results: Before the intervention, 70.3% of participants had poor knowledge and 29.7% had fair knowledge, while none achieved a good knowledge level. Following the intervention, all participants (100%) attained the good knowledge category. The mean knowledge score increased from 8.00 to 12.89, with an average improvement of 4.89 points, indicating a substantial enhancement in participants' understanding of dengue transmission, symptoms, and prevention. Conclusion: Community-based health education effectively improved knowledge of DHF prevention and reinforced community awareness of the PSN 3M Plus strategy. Integrating regular educational activities into primary healthcare programs may strengthen community participation and contribute to sustainable dengue prevention efforts.