The phenomenon of alpha band desynchronization (ERD) has been extensively studied as an electrophysiological correlation of individual intelligence differences. However, in Brazil, there is lack of research regarding the subject. The present study intended to verify the relationship between psychometric intelligence and neural efficiency, using event-related desynchronization, on children with different intellectual levels. Eight clinically healthy male children with an average age of 8.75 years, from the city of Belo Horizonte, participated in the study, divided into one high IQ group and one average IQ group. The children had their intelligence evaluated by psychometric tests and EEGs were collected in two different moments - during rest and while performing cognitive tasks. The results showed that the more intelligent children presented lower percentages of ERD when compared to the average IQ group, for frontal, parietal and temporal regions, though the differences between the groups did not achieve statistical significance. To sum up, this study presented a preliminary evidence of a methodology for neural efficiency studies using event-related desynchronization correlated to the psychometric intelligence tests used in Brazilian children. However, new studies are required to verify the generality of this methodology and the findings of the present study.