This study examines the effectiveness of a school-based healthy eating intervention program, the Healthy Highway Program, for improving healthy eating knowledge and healthy food choice behavior among elementary school students. Adopting the key aspects of social cognitive theory into the healthy eating promotion strategies at school, the program helped students raise the value of good health and nutrition, identify the benefits of adopting healthy eating patterns, develop practical skills for reading food labels and make healthy food choices through observation and hand-on experiences. After intervention, based on pretest-posttest design, statistically significant more students improved their healthy eating literacy by telling 'healthy (green light) and unhealthy (red light)' foods among their daily food choices. For example, after the intervention, statistically significant more K-2nd graders became to perceive French fries as 'red' food (from 41.9% to 61.2%). Similar changes happened among 3rd-5th graders regarding broccoli, bacon, banana, and green beans. Continuing positive intervention effects were found at the school lunch food choice behavior too. The positive findings of the present study can be attributed to the effective program design and curriculum content as well as to the educational workshops organized for teachers who volunteered to implement the Healthy Highway Programs into their classroom curricula.