Posyandu (Integrated Health Post) is a Community-Based Health Effort (UKBM) that plays a strategic role in providing basic health services for toddlers, pregnant women, and the elderly through promotive and preventive functions. This study aims to analyze the implementation of the Posyandu program, the level of community participation, and the contributions made by UIN Raden Mas Said Surakarta Community Service (KKN) students in Karangasem Utara Village, Cawas District, Klaten Regency. The study employed a descriptive method utilizing a participatory observation approach and a literature review. The results indicate that Posyandu activities are conducted regularly every month through the collaboration of health volunteers, village midwives, and Community Health Center (Puskesmas) staff activities include anthropometric measurements (weight, height, head circumference, and mid-upper arm circumference), health check-ups for pregnant women and the elderly, vitamin administration, and health education. Community participation is high, evidenced by the active awareness among mothers of toddlers regarding weighing results and the consistent attendance of pregnant women and the elderly. KKN students contributed through four key roles: providing technical support for measurements and recording in Maternal and Child Health (KIA) books; conducting educational outreach on nutrition and stunting and acting as motivators to encourage community participation. This synergy among the various stakeholders strengthens Posyandu's position as the frontline of community-based health services at the village level.