Background: The purpose of this study was to find the weight-related factors related to active attitude towards weight loss in children who are overweight or obese and their parents. Methods: A total of 252 elementary school children who were overweight or obese and their parents were surveyed on weight-related attitudes for one month in May 2003 in Kimhae. The definition of overweight and obesity was based on age and sex-specific Korean children's BMI references established in 1998. Results: Among the total, 64.5% of children and 76.4% of parents thought frequently about losing weight in children. Among the total, 52.8% of children and 47.6% of parents tried losing weight in children more than three times. In children, the factors related to frequent thoughts of losing weight were gender, body mass index (BMI), body dissatisfaction index, and the score of eating attitude (P<0.05). Parents' thought about their children's losing weight and the efforts to persuade their children to lose weight were related to children's frequent thought about losing weight. The children's factors related to trying to lose weight by themselves were age, BMI, and the score of eating attitude. The parent's factors related to children trying to lose weight were body dissatisfaction index of their children by parents, parent's eating attitude score, parent's thought about children's losing weight and making efforts to persuade children to lose weight by parents. The children's eating attitude was related to frequent thoughts about losing weight (odds ratio 1.05, 95% CI 1.03~1.07) and trying to lose weight more than 3 times (odds ratio 1.02, 95% CI 1.003~1.04) after adjusting for other factors. Likewise, parents' effort to persuade their childrento lose weight was related to children's effort to lose weight (odds ratio 2.62, 95% CI 1.34~5.1). Conclusion: Active attitude towards losing weight in overweight or obese children was related to parent's attitude to wards losing weight.