Numerous studies have investigated quantifying dietary intake according to the weight status of children and adolescents. However, studies on differences in quality among diets remain scarce. This study compared diet quality by weight status and examined correlations between quality of diet and obesity in children and adolescents. Two hundred fourteen children and adolescents aged between 9 and 18 years participated in this study (Normal weight n=104, Obesity n=110). The data related to food intake were investigated by dietary records, Diet Quality Index-International (DQI-I), and Nutrition Quotient (NQ) and then compared with Dietary Reference Intakes for Korean (KDRIs). In DQI-I, moderation factor (control of unhealthy foods) score was 21.7 in the normal weight group and 19.5 in the obesity group. The normal weight group showed a higher score for moderation factor than the obesity group (P＜0.001). Compared with KDRIs, vitamin B6, folate, vitamin C, vitamin E, calcium, potassium, and zinc intakes were insufficient in both groups. Multiple logistic regression analysis revealed that DQI-I moderation was negatively associated with obesity (OR=0.77, 95% CI 0.69-0.87) after adjustment for age, gender, income, and total energy intake. Our results suggest that children and adolescents require nutritional education to understand the importance of vitamin and mineral consumption. Especially, education for children and adolescents with obesity needs to emphasize moderation of nutrient intake that can cause diseases with hyper-ingestion such as sodium and high calorie-low nutrition foods.