In preparing for community intervention programs with the participation of schoolchildren at Binh Duong province, a health education program was launched to strengthen the knowledge, attitudes, and practices concerning dengue hemorragic fever of junior high schoolchildren. Objectives: To determine the proportions of junior high schoolchlidren having correct knowledge, attitudes, and practices in dengue hemorragic fever prevention, before and after health education. Methods: An intervention study was conducted among 650 children at Chinh Nghia junior high school at Thi Dau Mot township of Binh Duong province.