The aims of this prospective study were (1) to examine whether quantitative and/or qualitative aspects of motor performance in 5- to 6-year-old children can predict attention-deficit–hyperactivity disorder (ADHD) 18 months later; (2) to investigate whether this relation is also present in oppositional defiant disorder and conduct disorder (ODD/CD). Quantitative and qualitative aspects of motor performance were tested in a selected community sample (n=401; 232 males, 169 females; mean age 6 years 4 months, SD 6 months, range 5 years 4 months to 7 years 11 months) using the Maastricht Motor Test. Eighteen months later, standardized psychiatric information was obtained with the Amsterdam Diagnostic Interview for Children and Adolescents: 35 children were classified as having ADHD, and 92 children as having ODD/CD. Weighted analyses were used in logistic regression analyses to investigate predictive values. Unlike quantitative aspects of motor performance, qualitative aspects were predictive of ADHD. Motor performance was not predictive of ODD/CD.