Background: Looked-after children (LAC) frequently experience greater mental health challenges than the general child population. There has been a call for greater focus on early preventative interventions and priority access to specialist mental health support for this population. Brief mental health screening tools often provide the gateway to services and yet there is a lack of suitable assessment tools available for LAC. The current study is the first to explore the perspectives of foster carers and CAMHS clinicians’ in relation to the use of two brief screening tools; the Strengths and Difficulties Questionnaire (SDQ) and the Brief Assessment Checklists (BAC’s). Method: Qualitative data was collected via semi-structured telephone interviews and face-to-face focus groups with female foster carers (N=13) and clinicians working in a CAMHS setting (N=9). Results: Thematic analyses generated six themes which were organised into three superordinate themes centred around: 1) relevance to LAC, 2) using measures to inform care planning and; 3) current problems when using psychometric measures within the LAC population. Foster carers and clinicians emphasised the need for a comprehensive understanding of LAC given the complexity of their difficulties. There was acknowledgement that psychometric measures could facilitate and contribute to this by highlighting difficulties, providing accurate feedback to carers and clinicians, and enabling access to support. However, both groups seldom felt that current measures were nuanced enough to adequately capture the needs of LAC. Conclusion: Screening tools play a crucial role in identifying the mental health needs of LAC and facilitating access to services. Further research is needed to establish the ability of such measures to increase the sensitivity of the complex needs’ assessment of LAC. A number of clinical recommendations are also discussed in relation to the assessment of mental health in the LAC population.