The diagnosis of Attention Deficit Hyperactivity Disorder (ADHD) is mainly based on structured scales, such as Conners' ADHD Rating Scale (EDAH in the Spanish version) and DSM interviews. The use of technologies in neuropsychological assessment, such as the AULA virtual reality based test leads to more accurate diagnosis. The current study presents findings from analyzing the external validity of AULA and its contribution to the diagnosis of ADHD. Four hundred and seven children (272 girls and 135 boys) from 6 to 16 years old (213 with ADHD diagnosis, 105 inattentive children, 108 combined-type, and 194 controls) were evaluated. First, a factor analysis of AULA variables was conducted in order to reduce data to factor and 5 factors or components that account for 82.37% of the total variance were obtained from 407 subjects, namely, sustained attention, impulsivity control, processing speed, response variability, and control of motor activity. Second, a discriminant analysis was then performed on data obtained by participants from whom the five factors were obtained, showing that AULA presents moderate levels of both specificity and sensitivity. Finally, in order to study whether AULA adds relevant information in the diagnosis of ADHD, a cluster analysis was carried out, showing 4 clusters in the analysis of conglomerates with the control group and 6 groups of clusters in the ADHD group. In summary, AULA test shows adequate external validity, allows correct classification of children with and without attentional problems, and confirms and provides additional ADHD diagnostic information that it is essential for the design of interventions.