© 2020 Elsevier Ltd Background: The assessment of Attention Deficit Hyperactivity Disorder (ADHD) requires the integration of many different sources of information. These sources of information are often subjective, so objective measures like the QbTest can be an asset to healthcare teams that diagnose ADHD. Method: The present study used a mixed-methods design to examine the impact of the introduction of the QbTest in Irish Child and Adolescent Mental Health Services (CAMHS). The main analysis consisted of three focus groups with clinicians (n = 19) working in CAMHS. A concurrent pilot was run that consisted of the administration of 50 questionnaires to CAMHS clinicians (n = 17), service users (n = 15) and their families (n = 18). Results: Thematic analysis of focus group transcripts highlighted that clinicians considered the QbTest a valued addition to ADHD assessment as it was efficient, objective and clear. Survey data suggested that clinicians, service users and their families found the QbTest helpful and acceptable. Conclusions: The findings indicated that participants in the present study (clinicians, service users, parents and guardians) all had positive reactions to their experience with the QbTest. Recommendations for future research are discussed.