Background Computed tomography angiography (CTA) is widely used as the preferred imaging modality in the diagnosis of aortic dissection with high diagnostic value. However, high radiation dose associated with CTA remains a concern, especially for young patients. Little research is available regarding the correlation between age groups and CT dose values. Aims To investigate the clinical performance of CTA in diagnosing aortic dissection and determine the correlation between age groups and corresponding CT dose values based on a single centre experience. Methods A total of 204 patient records were retrospectively reviewed for analysis of the CTA examinations over a period of 12 months. CTA findings regarding the type and extent of aortic dissection were analysed, while radiation dose values in terms of volume CT dose index (CTDIvol) and dose length product (DLP) were compared between different age groups (<30 years, 31-40, 41-50, 51-60, 61-70, and >70 years). Results Of 204 patients, 170 had abnormal CTA findings with Stanford type A dissection diagnosed in 38 cases and type B dissection in the remaining 132 cases. There were significant differences in CTDIvol and DLP dose values between age groups (p=0.039-0.048) with the groups 31-40 years old having the highest radiation dose than other groups. The mean effective dose for all patients is 11.18mSv. Conclusion CTA is an accurate imaging modality for diagnosis of aortic dissection; however, reduction of radiation dose is necessary, especially for younger patients due to direct correlations between patient's age and corresponding dose values.