The CYP-IAPT programme emphasises the meaningful contribution session-by-session routine outcome monitoring (ROM) can make to clinical practice and its importance in highlighting services’ effectiveness. Two studies on issues related to the implementation of ROM in children’s services were conducted. Study one was qualitative; twelve CAMHS professionals participated in focus groups. Themes identified included the idea that ROM could provide objectivity, could be collaborative and empowering. Concerns included how measures may adversely influence therapeutic sessions and how the information may be used by the service. These themes were used to develop a questionnaire about professional’s experience of and views on session-by-session ROM. In study two, 59 professionals from four CAMHS teams completed the questionnaire. It was found that only 6.8% reported “almost always” utilising session-by-session ROM. Detailed analysis of questionnaire responses suggested two sub-scales reflecting the perceived negative and positive impact of session-by-session ROM. It was found that clinicians who currently use session-by-session ROM hold stronger positive and negative beliefs than clinicians who do not. This study suggests that session-by-session ROM is not currently routine practice within CAMHS and highlights the importance of considering how this practice can be best implemented within this setting with reference to clinician attitudes.