Objective To assess the effectiveness of child health care professionals (CHP) in identifying psychosocial problems among children originating from industrialized and nonindustrialized countries and to assess whether parental concerns enhance CHP problem-identification. Study design During routine well-child visits data were collected from a sample of children aged 5 to 12 years of Dutch, Moroccan, Turkish, Surinam, and Antillean origin (response: 82%). CHP reported on psychosocial problems that they identified in children. Parents completed the Child Behavior Checklist (CBCL) and a questionnaire on concerns regarding their child's psychosocial development. Interpreter services were used to support parents in filling out questionnaires. Results Elevated CBCL total and internalizing problem scores were more prevalent among children from nonindustrialized countries (10% and 17%, respectively) than among children from industrialized countries (3% and 5%, respectively). About 30% of the Turkish and Moroccan children with an elevated CBCL score were identified by CHPs compared with 60% of the children from industrialized countries. Parental concerns on their child's psychosocial well-being were related to elevated CBCL scores. Concerns were not related to CHP problem-identification. Conclusions Better methods to support parents in disclosure of their concerns regarding the psychosocial development of their children may enhance CHP-identification of problems, especially among groups from nonindustrialized countries. (J Pediatr 2010;156:277-84).