['This study sought to assess whether lower school performance in childhood is a risk factor for dementia in old age.', 'Participants aged 60 years or more (n = 111) with documented proof from schools were included. Grades in three subjects - Portuguese, mathematics, and geography - were recorded and the mean final grade in all disciplines were assessed. Dementia was diagnosed using DSM-IV criteria. Sociodemographic data, school performance, and years of education were ascertained by checking documents issued by schools. Health status (hypertension and diabetes) were self reported. Regression models were used to assess the role of school performance and years of education on the risk of dementia.', 'Dementia was diagnosed in 22 subjects. Higher school performance and years of education decreased the chance of dementia by 79% (OR = 0.21; CI 0.08-0.58) and 21% (OR = 0.79; CI 0.69-0.91), respectively. After adjustments for sociodemographic and clinical variables, only school performance remained statistically significant (OR = 0.06; CI 0.01-0.71).'] Is school attainment in childhood an independent risk factor of dementia in late life : results from a Brazilian sample?