Aim: To compare mental health (MH) outcomes of and service use by children born under 1500 g in Ireland with a matched control group. Method: Using a retrospective cohort design, semi-structured and standardised MH assessments were conducted with parents, teachers and youth. Results: A total of 64 of 127 surviving children from a very low birth weight (VLBW) cohort from a National Maternity Hospital participated at a mean age of 11.6 years (s.d. 1.0), along with 51 matched controls. More VLBW children received clinical or borderline scores when rated by parents [chi2 (1, n = 114) = 7.3, p = 0.007] or youths [chi2 (1, n = 114) = 4.83, p = 0.028], but not by teachers [chi2 (1, n = 114) = 1.243, p = 0.463]. There was no increase in the use of MH services. A main effect of birth weight remained on the parent Strengths and Difficulties Questionnaire [F (1, 88) = 5.07, p < 0.05) after controlling for intelligence quotient (IQ) and socio-economic status (SES), but only on hyperactivity in males. SES, rather than IQ or birth weight, predicted identification of problems by teachers [F (1, 82) = 6.99, p = 0.01). Interpretations: Teachers miss MH difficulties and are influenced more by SES than by IQ or birth weight. This has implications for MH service access. Initial perinatal investment needs to be matched with ongoing surveillance and psychoeducation to ensure that disorders are recognised early and offered appropriate interventions.