Abstract Attention deficit hyperactivity disorder (ADHD) is a clinical and diagnostic heterogeneous picture. This study analysed the association of functional polymorphisms in DAT1 VNTR 3’ UTR and DRD4 VNTR Exon III candidate genes, and the neuropsychological characterisation of attention and executive functions of a group of children with ADHD vs. controls. 32 patients and 51 controls were selected. The DAT1 10-repeat allele appeared more frequently in the two groups (cases: 0.93/control: 0.82), showing an OR: 2.5 (IC 95%: 0.684-9.133; p: 0.158). In DRD4, the 4-repeat allele shows the highest occurrence (cases: 0.62/controls: 0.60). None of the markers presented a significant association after a direct analysis, but the DRD4 7-repeat marker showed a positive risk when performing a Bayesian logistic analysis (coefficient: −1.69; OR: 5.39 CI 95%: 1.167-40.97). On the other hand, when considering association with cognitive performance, a positive risk for processing speed and attention tasks was identified.