Recent literature has increasingly highlighted the contribution made by gene-environment interaction (G × E) on child’s development. Only a few studies have explored the interaction between the child’s genotype of the dopamine active transporter gene (DAT1) and the family environment. The aim of this study, in a normative sample of 124 families of children between 6 and 11 years of age, was to examine children’s emotional-behavioural functioning, considering the interaction between the child’s DAT1 genotype and (separately for mothers and fathers) the parental psychological profiles, parenting stress and dyadic adjustment. The results showed the presence of G × E effects on the relationship between paternal and children’s psychological profiles and between paternal stress and children’s emotional-behavioural functioning. The study suggested a role of DAT1 in the complex gene-environmental interplay, contributing to the knowledge on risk and protective factors underlying the psychopathological risk in childhood.