This study comprised part of a larger cross-sectional survey performed in Hungary in the period 2005-2006, which was designed first to reveal the representative age-, gender- and height-specific percentile values for the systolic blood pressure (SBP) and the diastolic blood pressure (DBP) in Hungarian children aged 11-16 years. The second aim was to determine the prevalence of overweight and obesity. Analyses were performed on 14,290 Hungarian children aged 11-16 years. All blood pressure (BP) measurements were made with a validated, automated, digital device. The criteria recommended by international guidelines were used. The prevalence of overweight and obesity among the Hungarian children was found to be 23.4% (3347 adolescents; International Obesity Task Force criteria). Previous studies have reported that the strongest correlation is observed between the BP values and weight, and our results are in accordance with this. Regional differences in morphometry (different prevalences of overweight and obesity) and the genetic background, disparate eating habits and other cultural factors may account for the differences in BP levels during childhood. As the prevalence of overweight and obesity is increasing worldwide, it is important that countries carefully monitor the weight and BP status of their children and adolescents.