We studied ultrasonographic signs of early atherosclerosis in relation to established risk factors of cardiovascular disease in 43 obese school-age children compared to 28 non-obese controls. The groups did not show significant differences in age, gender ratio and body height. Mean carotid intima-media-thickness (IMT), carotid haemodynamic parameters, flow-mediated dilatation of the brachial artery (FMD), and biochemical markers of dyslipidaemia were measured and correlated. IMT was significantly increased (0.62 mm vs. 0.46 mm, P <0.001) and="" fmd="" was="" markedly="" reduced="" (10.9%="" vs.="" 18.8%,=""> P <0.001) in="" the="" obesity="" group.="" differences="" in="" imt="" and="" fmd="" persisted="" after="" adjustment="" for="" body="" mass="" index="" (bmi)="" and="" blood="" pressure="" on="" ancova.="" bmi="" was="" highly="" associated="" with="" increased="" imt=""> r =0.58, P <0.01) and="" reduced="" fmd=""> r =-0.42, P <0.01), as="" were="" blood="" levels="" of="" total="" cholesterol,="" ldl="" cholesterol="" and="" apo="" b.=""> Conclusion:Childhood obesity seems to contribute to the development and progression of early atherosclerosis, particularly in combination with hypertension and dyslipidaemia. In order to prevent coronary atherosclerosis and other cardiovascular complications, it is vital to control obesity starting from childhood. Ultrasonography of the arterial wall may be used in a clinical setting to identify high-risk patients among severely obese children.