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. AIM: To measure and compare computed tomography (CT) radiation doses delivered to patients in public pediatric 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 based on 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 were confirmed in Saudi Arabian pediatric CT departments were significantly higher than those in their Australian equivalents. CONCLUSION: CT dose varies substantially across Australian and Saudi Arabian pediatric hospitals. Thus, diagnostic reference levels should be established for major anatomical regions to standardi se dose.