OBJECTIVE To identify those patients most likely to fail to attend dental appointments. METHODS Retrospective analysis of the attendance pattern of patients. METHODS A National Health Service practice in Kent. METHODS Dental records of 1000 patients. METHODS Data (age, gender, plaque score, treatment planned, whether the patient was exempt from charges, distance between their home and the practice) were related to attendance history. RESULTS 34.8% of patients receiving income support and 24.8% of children failed to attend compared with 18.6% of non-exempt adults. Differences between non-exempt adults and children [per cent difference 6.2%, CI = (0.6%, 11.8%)] and for those receiving income support [per cent difference 16.2%, CI = (6.2%, 26.2%)] were significant (P < 0.05). A significant improvement in the appointment failure rate was achieved using telephone reminders. CONCLUSIONS Patients exempt from dental charges (mainly children and those receiving income support) were more likely to have failed to attend for their appointment. Whereas the attendance of children may be outside their control in some cases, we hypothesise that factors such as poverty in the group receiving income support may be an important influence in whether these patients feel able to attend for their appointments.