Abstract: Objective: To investigate the radiation dose levels of adult head and chest CT examinations at primary healthcare institutions in a suburban district of Beijing, evaluate their appropriateness, and provide a basis for establishing diagnostic reference levels (DRL) in the region. Methods: Data were collected from 15 CT scanners in 11 primary healthcare institutions within the district, including scan parameters and radiation dose data for head and chest CT examinations. Statistical analysis was performed to evaluate the distribution of radiation dose levels, and the results were compared with domestic and international DRL recommendations. Results: The DRL for head CT, defined by CTDI and DLP, were 59.83 mGy and 814.08 mGy·cm, respectively. The DRL for chest CT were 13.68 mGy and 444.51 mGy·cm, both of which are lower than the national industry standards. The DRL for head CT were better than those in most other countries, while the differences in other parameters were not significant. The radiation dose levels at tertiary hospitals were significantly lower than those at primary hospitals, and significant differences in scanning parameters and radiation dose were observed across hospitals . Conclusion: The overall radiation dose levels for adult head and chest CT examinations at primary healthcare institutions in the region are within reasonable limits. However, there is still room for optimization of CT scan parameters in some primary healthcare institutions to further reduce patient radiation exposure.