Young people living in the state care system are often reported to experience poorer levels of mental health and wellbeing. Government policy encourages a holistic approach to the assessment of all aspects of health and wellbeing of these young people. The Strengths and Difficulties Questionnaire (SDQ), a mental health screener for young people aged four to 16 years, was administered to a number of young people living in state care and a sample not living in state care as part of the Youth Development Study being undertaken at Queens University Belfast. The findings from the study showed that a higher proportion of young people living in state care reported scores on the SDQ that indicated a higher propensity to problem behaviour at both stages of the survey when aged 11/12 years and 14/15 years. The findings show that the SDQ is a tool that may assist professionals to make an informed decision on the health and wellbeing of young people entering the care system and possibly can lead to an empirically assisted decision on intervention planning. (Contains 4 tables and 2 figures.)