BACKGROUND: This study was undertaken to show the association between obesity and hyperlipidemia among the children. METHODS: In March 2000, while conducting a comprehensive health examination, we analyzed 2011 children from the first grade of primary schools in Taichung City in Taiwan. To study the association between obesity and hyperlipidemia, the t test, chi-square analysis, and multivariate logistic regression were used. RESULTS: There were 1057 boys (52.56 percent) and 954 girls (47.44 percent). The mean age was 7.27 +/- 0.46 years. The proportion of overweight was 11.07 percent in boys and 11.64 percent in girls. The proportion of obesity was 14.19 percent in boys and 12.89 percent in girls. After controlling the other covariates, the multivariate logistic regression analysis showed that overweight was associated with a low level of high density lipoprotein cholesterol. Obesity was associated with hypertriglyceridemia, a high level of low density lipoprotein cholesterol, and a low level of high density lipoprotein cholesterol. CONCLUSIONS: Our findings disclosed that the prevalence of overweight and obesity was high in childhood. Early intervention to control and prevent childhood obesity might be warranted. Obesity was associated with hyperlipidemia in children. A wide-scale survey will be suggested in the future to establish causal-effect issues between obesiyy and hyperlipidemia.