In this study, 342 grade 4-6 elementary school students in Gyeonggi-do were recruited to determine their readiness to change food safety behavior and to compare their food safety knowledge and practices by the stages of change. The subjects were divided into three stages of change; the percentage of stage 1 (precontemplation) was 10.1%, the percentage of stage 2 (contemplation and preparation) was 62.4%, and that of stage 3 (action and maintenance) was 27.5%. Food safety knowledge scores in stage 3 (4.55) or stage 2 (4.50) children were significantly higher than those in stage 1 children (4.17) ( P < 0.05). The two food safety behavior items "hand washing practice" and "avoidance of harmful food" were significantly different among the three groups ( P < 0.05). Stages of change were significantly and positively correlated with food safety knowledge and practice. Age was significantly and negatively correlated with the total food safety behavior score (r = -0.142, P < 0.05). The most influential factor on the stage of change was a mother's instruction about food safety ( P < 0.01).