Background: Assessment of dental anxiety in children and adolescence is often based on the clinician’s experience and judgement. Accurate and reproducible assessment methods can enable a clinician to identify an anxious patient and tailor their treatment plan accordingly. This will help build rapport with the patient and lead to improvements in oral health while reducing dental avoidance. Aims: The aim of this study is to compare dental students’ behavioural based judgements of perceived dental anxiety with the self-report indices of the paediatric patient using the Facial Image Scale (Buchanan & Niven, 2002). Method: Paediatric patients (6-13yrs), attending the undergraduate Paediatric Clinic in the Cork University Dental School & Hospital, took part in the study. After completing a full medical history on the patient, students rated the patients’ anxiety level based on their own observational judgements. The patient was then asked to identify their current level of anxiety using the Facial Image Scale. Results: A small number of students ranked the patients anxiety level correctly while the majority of students overestimated the patients’ anxiety. Factors such as patient responsiveness, smiling, inquisitiveness and previous dental experience led students to believe the patient was calm. While behaviours such as, being unresponsive to conversation, restlessness and a reluctance to make eye contact was interpreted to indicate a higher anxiety level. Conclusion: The introduction of the Facial Image Scale provides a clear and accurate measurement of dental anxiety in paediatric patients, which can inform the patient-clinician interaction.