Purpose: This study was conducted to develop and investigate the effect of a combined health promotion program for preschool children and their parents. Methods: Physical examinations were done for 993 preschoolers in 12 preschools. Their parents (n=727) completed a questionnaire on health status and health knowledge of their children and 35 teachers in preschools completed one on health knowledge of preschoolers. Based on the results of the physical examinations and survey, a combined health promotion program was developed. In order to evaluate the program, 35 teachers and 104 parents participated in the program. The effects of the program were tested and health knowledge before and after the program was analyzed. Results: Health knowledge of parents and teachers increased significantly after attending the combined health promotion program. Conclusion: In order to promote the health of preschoolers, parents and teachers need to participate in combined health programs that provide an opportunity for preschoolers to have a physical examination and their parents to learn about the health care for their children.