A total population of 589 6-year-old children were screened for neurodevelopmental/neuropsychiatric disorders by questionnaires to parents and preschool teachers, and by examination of motor abilities at the Child Health Center. Fifty screen-positive and fifty screen-negative children were assigned for complete neuropsychiatric assessment comprising a detailed history, psychiatric and neurodevelopmental assessment, neuropsychological examination and speech/language evaluation. Comprehensive diagnoses were made on the basis of all the available information. In the total population, 63 children (10.7%) with disorders were identified, 10 of whom had a diagnosis established before the study. The prevalence rates for deficits in attention, motor control and perception (DAMP) were 5.3 to 6.9%, for attention deficit hyperactivity disorder (ADHD) they were 2.4 to 4.0% and for mental retardation, 2.5%. Co-morbidity was established for ADHD on the one hand and DAMP, mental retardation and Tourette syndrome on the other. The findings suggest the need for a school entrant screening examination for the types of problems examined in this study.