Attention-Deficit/Hyperactive Disorder is one of the most prevalent developmental disorders in childhood and adolescents. Individuals with ADHD is found to be at risk for social and academic impairments. The aim of this study was to examine the relationship between Executive Functions (EF) and Attention-Deficit/Hyperactivity Disorder (ADHD) in preschool-aged children. Deficits in EFs are currently considered to represent an important weakness in this clinical group. To extend our knowledge about the relative contribution such functions have for the development of ADHD, it is essential to investigate whether this association is detectable during the preschool-years. More knowledge about the early signs and symptoms of ADHD can contribute to early detection of children at risk for developing the disorder and intervention procedures can be implemented to limit the associated negative life outcomes.