This chapter examines the critical role of behavioral interventions in infectious disease prevention, focusing on Vietnam as a compelling case study. Vietnam’s proactive public health strategies from grassroot levels, rooted in the principle “Phòng bệnh hơn chữa bệnh” (prevention is better than cure), have yielded notable successes in combating various infectious disease threats, including the recent COVID-19 pandemic. The chapter consolidates the global evidence base for behavioral interventions, highlighting the importance of understanding human behavior and cultural contexts and implementing timely public health measures. It analyzes Vietnam’s public health system, its strategic approaches, and specific interventions, such as hand hygiene campaigns, safe sex education programs, and vaccination programs. The chapter also addresses the challenges encountered, including emerging pathogens, antimicrobial resistance, urbanization, and vaccine hesitancy while exploring the influence of social determinants of health. It further examines the intervention life cycle in Vietnam, assesses alignment with United Nations Sustainable Development Goals, and examines the influence of Vietnam’s evolving economy on intervention effectiveness. The chapter concludes by offering recommendations for strengthening behavioral interventions in Vietnam and similar low- or middle-income settings, emphasizing the need for culturally targeted strategies, community engagement, and multisectoral collaboration.