BACKGROUND The higher brain functions, together with the devices that sustain them, are essential assets belonging to human beings which are used to situate themselves in the world. They can be studied by conducting neuropsychological tests, the results of which vary according to demographic factors, such as age, sex, hand dominance, culture and level of schooling. The socioeconomic level (SEL) is another factor to be taken into account and must also be evaluated. OBJECTIVE Our objective was to evaluate and analyse the influence of SEL on the results obtained from neuropsychological tests carried out in normal school-age children. METHODS We studied 401 normal children, of both sexes, taken at random, at the beginning (1st grade, 6 years old) and at the end (7th grade, 12 years old) of elementary school and belonging to two different SEL: high and low. Schools belonging to different categories were selected: public, private, urban and suburban. A battery of tests that is commonly used in Neuropsychology was utilised to evaluate laterality, spatial orientation, integration (Bender's test and the Rey figure test), attention, memory and the areas of language, gnosis and praxis. RESULTS Significant differences were found in relation to the SEL in the 1st and 7th grade tests: 20/27 (74%) and 17/27 (62%), respectively. These always meant lower results in the low SEL, except body scheme, ideomotor praxis and phonological coding, which in the 7th grade run in the opposite direction. Results were not related to the type of school (urban-suburban, public-private), sex, laterality or teachers' characteristics. Differences were more striking in the area of language, basic devices (attention, memory) and in the tests that integrate several different functions (Bender's test, Rey figure test). CONCLUSIONS SEL is linked to the results obtained in neuropsychological evaluation tests. There is a direct relationship with low results in the low level. There is also a correlation between certain family characteristics associated to the SEL and the scores in the cognitive evaluation tests.