Abstract: In the present day scenario, ionizing radiation is widely used to diagnose many diseases both in developed and developing world. Excessive use of ionizing radiation has an increased risk of fatal cancer. It is believed that the awareness of medical doctors about hazards of ionizing radiation and radiation dose values is one of the first step in protecting patients from radiation exposure. The aim of this study was to assess medical doctors’ knowledge about patients’ ionizing radiation exposure dose and its associated risks at Jimma University Specialized Hospital.Descriptive cross- sectional study was conducted among 110 physicians working in Jimma University Specialized Hospital.A structured, self-administered and pre-tested questionnaire was used to collect data from sampled population.