The use of validated psychological tests provides valuable evidence to specialists in a multiplicity of activities (e.g., predicting diagnoses, guiding treatment and follow-up plans, guiding the job selection process and vocational orientation, determining disability levels for medico-legal purposes). However, a psychological instrument is not generally adapted and standardized in the country in which it is intended to be applied. In Argentina, the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV) was standardized in the Buenos Aires Metropolitan Area; but did not include samples from other regions across the vast country. This situation is problematic, because Argentina presents disparities in its socio-demographic characteristics across the territory, and an accurate interpretation of intelligence test performance, depends on the use of appropriately standardized data. Hence, a quantitative non-experimental, exploratory-descriptive study was conducted to determine the importance of obtaining locally standardized data for WISC-IV. To this end, the indices obtained from 520 children and adolescents aged 6 to 14 years (grouped according to age ranges 6-8, 9-11 and 12-14) were comparatively analyzed, by analyzing two Argentine adaptations (Buenos Aires and Resistencia). Results revealed differences between normative data from the country's different regions in four indices, which included both aspects of general cognitive functioning (i.e., CIT) and more specific processes (i.e., working memory - IMO, processing speed - IVP, and perceptual reasoning IRP). These results suggest that the assessment of students, according to non-locally established standardized data, could lead to interpretative errors regarding their cognitive abilities. Thus, the study contributes to knowledge about the importance of using contextually appropriate standardized data in the implementation of intelligence tests, to arrive at evaluations that avoid over- or under- estimating students' abilities.