Background Defining quality in health presents many challenges. The Institute of Medicine (IOM) defined quality clinical care as care that is equitable, timely, safe, efficient, effective and patient centred. However, it is not clear how different stakeholders within a child and adolescent mental health service (CAMHS) understand and/or apply this framework. This project aims to identify key stakeholders“ understanding of the meaning of quality in the context of CAMHS. Method The study sample comprised of three groups: (i) patients and carers, (ii) CAMHS clinical staff, and (iii) commissioners (Total N = 24). Semi-structured interviews were used to collect data and thematic analysis was applied to explore participant’s views on the meaning and measurement of quality and how these might reflect the IOM indicators and their relevance in CAMHS. Results An initial barrier to implementing quality care in CAMHS was the difficulty and limited agreement in defining the meaning of quality care, its measurement and implementation for all participants. Clinical staff defined quality as personal values, a set of practical rules, or clinical discharge rates; while patients suggested being more involved in the decision-making process. Commissioners, while supportive of adequate safeguarding and patient satisfaction procedures, did not explicitly link their view on quality to commissioning guidelines. Identifying practical barriers to implementing quality care was easier for all interviewees and common themes included: lack of meaningful measures, recourses, accountability, and training. All interviewees considered the IOM six markers as comprehensive and relevant to CAMHS. Conclusions No respondent individually or within one stakeholder group identified more than a few of the indicators or barriers of a quality CAMHS service. However, the composite responses of the respondents enable us to develop a more complete picture of how to improve quality care in practice and guide future research in the area. Electronic supplementary material The online version of this article (doi:10.1186/s12913-017-2080-z) contains supplementary material, which is available to authorized users.