Purpose: This study evaluated the association between excess weight and quality of life (QoL), symptoms of anxiety, caries experience and socio-economic factors in a representative sample of 8- to 10-year-old children from three public schools of Piracicaba (SP, Brazil). Materials and methods: The Autoquestionnaire Qualité de Vie Enfant Image was applied to explore family and social relations, activities, health, body functions and separation domains, and, by means of the Multidimensional Anxiety Scale for Children, symptoms of anxiety were screened. Clinical examination was performed using DMFT/dmft indexes to assess oral health and caries experience. Medical and nutritional history, parents’ schooling, monthly income and ownership of household goods and services were also evaluated. Results: Of the 313 subjects included, four subjects were underweight, 188 normal weight, 67 overweight and 54 presented obesity (38.7% with excess weight). Measures of QoL, anxiety scores and caries experience did not differ between groups. The regression model showed a significant association between excess weight and the ownership of household goods and services (OR = 5.4/CI = 1.6–18.3). Conclusions: High prevalence of excess weight was observed among prepubertal children, emphasizing the need for continued health programmes to limit risk factors for obesity. QoL, anxiety scores and caries experience did not differ between subjects with different body weights, although children from public schools with higher ownership of goods and services were more likely to present excess weight.