ObjectiveTo develop children's basic knowledge and activities to solve the dengue problem, and to evaluate the results from children's activities. MethodsParticipatory Action Research (PAR) was applied in five steps: 1) preparation step; 2) assessment step; 3) children's activities planning step; 4) implementation step; 5) evaluation step. Basic knowledge of dengue was evaluated by questionnaires (17 items) and analysis pre and post-activities by a Chi-square statistic test. The children's understanding of the dengue problem was evaluated by drawing pictures and participation of children's activities. Larval Indices (BI, HI, and CI) were ratio analysis which related dengue outbreak measurement. ResultsThree groups for children’ activities were: 1) group leaders (13 children); 2) general children; 3) a support group from the community. “Education of dengue learning”, “dengue prevention campaign”, and “the recycle garbage bank” were core children's activities. Most children's knowledge question items showed an increase from pre-activities to post-activities, and a half of all questions items were statistically significantly different (P<0.05). There were five categories of children's reflection from the drawn picture that showed understanding of the solution to dengue problems and methods for eliminating sites of mosquito breeding in the community. Their households had increased garbage management, and thus decreased numbers of mosquito breeding types such as larval indices (BI, HI, and CI) which decreased from before the activities (93, 30, and 14) to after them (7, 5, and 1). Furthermore, no instances of dengue morbidity or the mortality rate occurred during the study. ConclusionsAlthough there was an increase in the children's knowledge and activities, and a decrease in larval indices ratio, the high risk of a dengue epidemic might be found because the ratios of larval indices were based on community's behaviors. Thus, it is essential for children and all stakeholders in and out of the community needed to better combat the dengue problem.