AIM To investigate the current prevalence and trend of overweight in young schoolchildren in Umeå, Sweden. METHODS Two cross-sectional samples of children were studied: 1115 randomly selected children from preschool class to grade 6 (aged 6-13 y) attending school in 2001 and a matched sample of 507 schoolchildren from grades 0, 1 and 4 (aged 6-11 y) attending school in 1986. Overweight was defined according to age- and gender-specific body mass index (BMI) cut-off values, corresponding to BMI values of 25 kg/m2 (level 1) and 30 kg/m2 (level 2) at late adolescence. RESULTS In the population from 2001, the prevalence of overweight was 23% (18% at level 1, 5% at level 2). The prevalence differed with age, with a higher prevalence at the ages of 6 and 13 y. Comparing children from grades 0, 1 and 4, attending school in 1986 and 2001, respectively, the total prevalence of overweight was twice as high in 2001 as in 1986. Regarding severe overweight (level 2), the difference was even larger (five times). In the 1986 sample, the prevalence of overweight did not differ between girls and boys, while significantly more girls than boys were overweight in 2001. CONCLUSION In this sample of young children from Sweden, the prevalence of overweight doubled over the past 15 y and severe overweight increased even more, suggesting a need for intensified preventive efforts in young schoolchildren.