OBJECTIVE To identify issues of importance to adolescent patients surrounding the delivery of orthodontic treatment under the National Health Service (NHS), which can form the basis of a tool to examine patients' perceptions of NHS orthodontic treatment. DESIGN Study using qualitative research methods. SETTING Patients were recruited from the orthodontic departments at Derriford Hospital and Bristol Dental Hospital, and from Specialist Orthodontic Practices in Plymouth and Solihull. SUBJECTS A rolling sample of patients from a list of orthodontic patients under treatment at each site was selected. Twenty-six patients took part in five focus group meetings. Three patients took part in semi-structured telephone interviews. METHODS Participants were invited to participate in either a focus group meeting or a telephone interview. The transcripts of these meetings were analysed by two researchers working independently. Issues of importance to patients regarding the delivery of orthodontic treatment under the NHS were identified. RESULTS The issues identified included being treated with respect by the clinician and being included in discussions about treatment. Participants tended to rely on their peers for advice about what to expect from treatment. The patients also discussed the benefits to them of undergoing orthodontic treatment. These included an improved appearance and increased self-confidence. CONCLUSION This qualitative research has identified issues that are important to adolescent orthodontic patients. These issues will be used to form the basis of a patient-centred measure for auditing patients' perceptions of orthodontic treatment under the NHS.