Objectives: CBCT exposes the paediatric patient to a higher X-ray dose and risk than normal dental radiographs. This study has two components: an audit and service evaluation. The audit aims to assess whether the use of CBCT in a Paediatric Dentistry department at a London hospital complies with European guidelines (SEDENTEXCT). The service evaluation aims to explore the influence of CBCT on treatment planning. Methods: Two 6 month audit cycles were completed, where CBCT requests were audited to check whether image justifications comply with SEDENTEXCT. For the service evaluation, a total of 50 patient records were examined for the effect of CBCT on definitive treatment plans. Results: The first audit demonstrated 94% compliance with SEDENTEXCT. After instituting staff training in CBCT, compliance improved to 100%. In the service evaluation, 100% of CBCTs were found to provide information that impacted on the clinicians’ treatment planning, diagnosis and/or management. Of most significance, 44% of treatment plans were changed because of new information provided by CBCT. Conclusions: There are few studies investigating the use of CBCT in paediatric dentistry and the impact of this investigation. This service evaluation shows that CBCT can play an important role in optimising paediatric patient outcomes. The need for robust staff training in CBCT referrals to prevent over prescription is demonstrated in the audit cycles.