Background: To measure the knowledge levels of dentists and dental students about radiation doses of dental imaging techniques. Materials and Methods: A structured questionnaire containing 13 questions was conducted to 251 participants (168 dentists and 83 dental students). The first 6 questions were related to their personal and professional information, and the remaining 7 questions were about the participants’ radiation education and knowledge about radiation doses. Chi-square test was used to determine the relationship between categorical variables, and P < 0.05 was considered statistically significant. Results: The data from 144 (57.4%) women and 107 (42.6%) men were obtained. Gender was not effective on knowledge about radiation doses during dental imaging (p = 0.222). The knowledge of dentists working at the university was statistically higher than those working in the state hospital or private dental offices (p < 0.001). Of the participants, 43.4% (n = 109) stated that the craniofacial mode of cone beam computerized tomography radiates less radiation than the actual dose range, while 32.7% (n = 82) said they had no idea. Conclusion: Most of the dentists and dental students underestimated the actual radiation doses of dental imaging techniques. The dental curriculum should be revised to emphasize radiation protection during imaging. In addition, compulsory vocational postgraduate courses should be organized.