Obesity and lipid abnormalities in children may increase premature cardiovascular disease risk, but the relationship of dyslipidemia with adiposity among obese children is not well defined. The authors performed a cross-sectional analysis of children and adolescents (N=698) in 3 age groups (3–8 years, 9–11 years, and 12–18 years; 53% female, 81% African American, and 16% Hispanic) attending an obesity treatment program. More than 50% of the sample had abnormal levels of triglycerides (TG) or high-density lipoprotein (HDL) cholesterol or both. Only HDL cholesterol and TG were significantly associated with adiposity measures and insulin resistance (measured by homeostasis model assessment [HOMA]) and only in adolescents. All measures of adiposity, adjusted for age and sex, among adolescents were modest predictors of abnormal TG and HDL cholesterol, but these associations were attenuated when adjusting for HOMA. Despite the high prevalence of dyslipidemia in overweight children and adolescents, severity of adiposity appears to be a poor predictor of lipid values except among adolescents. Insulin resistance may in part mediate the relationship of adiposity and dyslipidemia among obese adolescents.