This study aims to estimate the knowledge and awareness of physicians about the hazards of radiological examinations on their health and on their patients. 466 questionnaires administered through a Google spreadsheet were answered by physicians from the 20 cities of Saudi Arabia. The sample included 167 radiologists, 106 neonatologists, 19 oncologists, 45 surgeons and 18 orthopaedists, 11 paediatricians and 100 physicians on different specialities. Only 133 of the physicians had received a radiation protection course in the workplace. A total of 73% from participants revealed many gaps in knowledge. For example, 51% of the respondents were unable to classify mammography as ionizing radiation and 69.3% did not know the recommended annual dose limit to the whole body of a radiation worker. The overall knowledge score ranged from 0% to 16.5% (mean 5.3%), with a low score among surgeons and orthopaedists. These results clearly indicate the heterogeneous knowledge for the physicians' and needs to be improved by implementation of pre-employment orientation courses or adding a subject in the under or postgraduate curricula.