This study was carried out to examine the effects of nutrition education program developed by Jincheon Public Health Center on preschool children's nutrition knowledge and dietary habits and the parents' dietary attitudes. The subjects of this study were five- and six-year-old children as well as their parents. A 5-week nutrition education program was implemented to 104 children in five day care centers, and 107 children in three day care centers were investigated as a control group. Activity tools designed for each lesson such as puzzles, food magnets, story, songs, Pierrot costume, and balls were used. Nutrition knowledge and dietary habits of children and dietary attitudes of parents were evaluated before and after education. Mean nutrition knowledge score in the education group was significantly higher than that in the control group after education (p < 0.001). Mean dietary habit score of three questions (three meals a day, eating at fixed time, eating breakfast) in the education group was also significantly higher than that in the control group after education (p < 0.01). In addition, parents in the education group showed significantly higher mean dietary attitude score than those in the control group even though they did not receive education (p < 0.001). Our nutrition education program was found to be effective in improving nutrition knowledge and dietary habits in preschool children as well as improving dietary attitudes in their parents.