Objectives: To assess the degree to which physicians and nurses working in preventive child health care (child health professionals [CHPs]) identify and manage psychosocial problems in children, and to determine its association with parent-reported behavioral and emotional problems, sociodemographic factors, and general and mental health history of children. Design: The CHPs examined the child and interviewed parents and child during their routine health assessments. The parents completed the Child Behavior Checklist. Setting: Nineteen child health care services across the Netherlands, serving nearly all school-aged children routinely. Subjects: Of 4970 children aged 5 through 15 years, eligible for a routine health assessment, 4480 (90.1%) participated. Main Outcome Measures: Identification and management of psychosocial problems by CHPs. Results: In 25% of all children, CHPs identified 1 or more psychosocial problems. One in 5 identified children were referred for further diagnosis and treatment. Identification of psychosocial problems and subsequent referral were 6 times more likely in children with serious parent-reported problem behavior according to the Child Behavior Checklist total problem score (8% of total sample). However, CHPs identified no psychosocial problems in 43% of these children and therefore undertook no action. Other child factors associated with CHPs' identification and referral were past treatment for psychosocial problems, life events, and academic problems. After adjustment for these, sociodemographic characteristics did not predict referral. Conclusions: The CHPs identify psychosocial problems in school-aged children frequently and undertake actions for most of them. Screening for psychosocial problems may be a promising option to reduce these problems, but accurate identification should be enhanced.