Aim: To measure and compare computed tomography (CT) radiation doses delivered to patients in public paediatric hospitals in Australia and Saudi Arabia. Methods: Doses were measured for routine CT scans of the head, chest and abdomen/pelvis for children aged 3-6 years in all dedicated public paediatric hospitals in Australia and Saudi Arabia using a CT phantom measurement cylinder. Results: CT doses, using the departments’ protocols for 3-6 year old, varied considerably between hospitals. Measured head doses varied from 137.6 to 528.0 mGy·cm, chest doses from 21.9 to 92.5 mGy·cm, and abdomen/pelvis doses from 24.9 to 118.0 mGy·cm. Mean head and abdomen/pelvis doses delivered in Saudi Arabian paediatric CT departments were significantly higher than those in their Australian equivalents. Conclusion: CT dose varies substantially across Australian and Saudi Arabian paediatric hospitals. Therefore, diagnostic reference levels should be established for major anatomical regions to standardise dose.