The aim of this dissertation was twofold: (1) To provide insight in the relationship between motor performance and executive functioning (EF) in 3- to 5-year-old children, and (2) to examine to what extent the operationalizations of motor performance and EF influence their relationship. One of the substudies compared the performance of 3- to 5-year-old children on the Movement Assessment Battery for Children-2 and the Zurich Neuromotor Assessment-2. It was found that these two tests measure similar as well as distinct aspects of motor performance. The second substudy, a systematic review, found highly varying correlations between motor performance and EF in 2- to 6-year-old typically developing children and children with Developmental Coord...