BACKGROUND AND OBJECTIVESThere are limited data on changes in the prevalence of overweight among the Saudi school children and on associated risk factors. We compared recent prevalence data (2012) with early data (1994–98) and assessed risk factors.DESIGN AND SETTINGData from a cross-sectional study of children in primary schools in two cities in Al-Qassim province.PATIENTS AND METHODSParental questionnaires were used to collect sociodemographic data and information on the child’s diet/exercise behavior. Children’s weight and height were measured. Current and previous data on overweight prevalence were compared and risk factors were assessed in a multiple logistic regression model.RESULTSThe sample consisted of 874 randomly chosen school children, aged 6–10 years; analysis was based on 601 with complete data. Current overweight prevalence was 16.9% and was higher in girls than in boys (29.7% vs. 11.7%, P value <.0001). Prevalence has risen in the last 15 years (overall: 16.9% vs. 10.1%; boys: 11.7% vs. 8.5%; girls: 29.7% vs. 11.5%; all P values <.05). Those who ate restaurant food ≥2 times/week were 2.4 times more likely (95% CI=1.26, 4.64) to be overweight and those who engaged in sports ≥2 hours/day were 0.5 times less likely to be overweight (95% CI=0.25, 1.20).CONCLUSIONThe overweight prevalence in primary school children in Saudi Arabia has risen significantly. The focus should be on developing obesity prevention programs for this population.