Overweight and obesity trends were investigated for schoolchildren and adolescents in Jeddah using data from 1994 and 2000. Individuals aged 10-20 years were selected using multistage stratified random sampling and direct measurements were made of body weight and height. Percentiles were calculated for body mass index (BMI), body weight and height for specific age and sex stratFor both sexes, BMI increased between 1994 and 2000 at the 50th percentile but higher still at the 85th and 95th percentiles. The increase in body weight and BMI were marked for all age groups; however boys showed the largest increase aged 10-16 years, whereas girls showed the lowest at 14-16 years. Public health intervention is crucial to prevent or reduce overweight and obesity among youth.