Many indices and scoring systems exist for assessing skeletal patterns and malocclusion but none have been universally adopted by teams providing orthognathic surgery in the UK. Using a standardised objective measure of a patient’s condition is important both for service provision, treatment allocation, and other clinical governance domains. The Severity and Outcome Assessment tool (SOA) developed by the British Orthodontic Society (BOS) and British Association of Oral and Maxillofacial Surgeons (BAOMS) provides a standardised method of assessing patients throughout the orthognathic pathway and lends itself to case selection, resource allocation and auditing treatment outcomes. The SOA uses 7 cephalometric skeletal, dental and soft tissue measures to produce an overall score.The SOA has been used by the current NHS Tayside orthognathic team since August 2006 to audit treatment outcomes. While we recognise that cephalometric analysis forms only one part of orthognathic treatment we believe that having an objective measure on which to assess treatment is useful. We present our experience of using this quick, simple and reproducible tool in auditing orthognathic treatment outcomes.