Objective: The aim of this study was to evaluate P-wave dispersion ( PWD) in Korean obese children, and to investigate the relationship between P-wave measurement, carotid intima-media thickness(CIMT). Method: Nineteen obese children including 4 girls and twenty-nine children including 11 girls with normal weight were enrolled this observational study. Results of anthropometric measurement, carotid IMT, laboratory assays including total cholesterol, HDL, LDL, triglyceride and fasting glucose, and electrocardiographic findings were recorded. Results: Median age of obese group was 9.8 years (range: 5.7-11.3) and 7.9 years in control group (range: 5.3-14.4years). Mean P wave duration was 88.5ms in obese group (68.7-104.9ms) and 84.5ms in control group(range: 62-93ms). Median value of PWD was 14.5ms in obese group (range: 13-30ms) and 13ms in control group (range: 7-28ms). Mean PWD was 14.5±5.8ms in obese group and 13.0±5.23ms in control group(p=0.05). Carotid IMT was 0.45mm in obese group (range: 0.40-0.5mm) and 0.44mm in control group (range: 0.37-0.51). There was no stastistical significance in CIMT between obese and control group(p=0.469). PWD was correlated with BMI (r=0.376, p=0.011), WHR (r=0.443, p=0.002), and triglyceride level (0.484, p=0.001). There was no correlation in PWD with age (r-0.127, p=0.204), mean P wave duration (r=0.245, p=0.104), and CIMT (r=0.09, p=0.278). Conclusion: PWD was in normal range in both group, but significant correlation was observed with BMI, WHR and triglyceride level. There were no significant difference in CIMT between obese children and control group.