AIM: This study investigated the diagnostic accuracy of the Strengths and Difficulties Questionnaire (SDQ) in a population of children born extremely preterm (<26wks gestation). METHOD: Parents and teachers of 219 extremely preterm children (118 females, 101 males; age 11y) were asked to complete the SDQ to screen for psychological problems. Multi-informant ratings were aggregated using two methods: combined (parent or teacher rated the child with problems) and pervasive (parent and teacher rated the child with problems). Psychiatric diagnoses were assigned using the Development and Well-Being Assessment. RESULTS: Pervasive ratings had the greatest diagnostic accuracy for emotional disorders (89%), conduct disorders (94%), attention-deficit-hyperactivity disorder (ADHD; 90%), and autism spectrum disorders (ASDs; 94%), but were associated with low sensitivity (