Non-attendance for first outpatient appointments at Child Mental Health Clinics is a common problem affecting efficient use of resources, as well as staff morale. This study demonstrates that requiring families to confirm that they want an appointment, in order to receive one, significantly improves the attendance rate for first appointments, compared to two other commonly used procedures: a reminder letter before the appointment is sent, and a standard appointment letter. Furthermore, this procedure did not appear to reduce accessibility to the service.