Objectives:To assess emergency doctors’ knowledge of radiation exposure doses and risks, as the increasing use of radiological investigations in emergency medicine practice is very concerning because of the associated risk of cancer.Methods:Doctors from different specialties and with different levels of training working in emergency departments of 8 hospitals in Jeddah, Kingdom of Saudi Arabia, filled out a questionnaire. Participants estimated the radiation doses of different imaging modalities and answered questions regarding possible associated risks.Results:One hundred seventy-one doctors returned completed questionnaires. The overall correct dose estimation rate was 20.8%. Doses were more correctly estimated by consultants versus specialists and residents (p=0.007), and by emergency physicians versus doctors from other specialties (p=0.05). The correct answer rate was insignificantly higher among doctors with formal training on radiation protection (p=0.065). The overall correct answer rate was unsatisfactory for 4 questions assessing physicians’ knowledge of risks. Questions about the lifetime risk of cancer due to ionizing radiation were more correctly answered by consultants versus residents and specialists (p=0.05). Specialists were more knowledgeable about the risk of imaging on fetuses (p=0.05). Doctors with formal training answered 3 out of 4 questions more correctly than doctors without formal training, but no difference existed between them regarding imaging modalities, that they selected for pregnant patients (p=0.297).Conclusion:Doctors working in emergency departments had poor knowledge about radiation doses and risks. This issue warrants urgent attention.