Background: Medical diagnostic radiation is manmade sources of exposure in medical practices. Ionizing radiation yields known health hazard that may vary from skin burn to cancer or death. In Ethiopia, health facilities are growing in number with the increasing facility of radiology services. However, the number of personnel, the provision of spare part of machine, quality assurance and other aspect has not grown with demand of safety. Objectives: The study was designed to assess the status of radiation exposure due to diagnostic xrays among patients and personnel. Methods: Cross-sectional study was carried out in 43 functional diagnostic x-ray institutions from January to February 2005 in Addis Ababa. A total of 215 patients who were examined for chest posterior-anterior (PA) were randomly selected. In addition, all radiology personnel who had dose report of the year 2004 were the study subjects. National Radiation Protection Authority completed radiation surveillance and quality control records of institutions were also considered. Results: The mean (SD) skin entrance dose of patients was 1.877(1.546) mSv. Out of the total 215 patients, 206(95.8%) of patients’ shallow dose and 191(88.8%) patients entrance deep dose were greater than 0.4mSv. The annual mean (SD) skin entrance dose for radiology personnel was found to be 0.407(0.225) mSv. According to records analysis of the National Radiation Protection Authority quality control, 15(19.2%), 13(16.7%) and 17(21.8%) of institutions machines were deviated with in unacceptable range in their generator voltage, the machines timer and, their collimation and beam alignment respectively. Multi variate analysis indicated that exposure setting v i i i greater than 25mAS [OR= 3.141; 95% CI = (1.170-8.432)] had impact on patients’ received dose to be high. Conclusion: Adult patients examined for chest-PA entrance dose was abnormally high. Thus, great efforts will be expected from different sectors of the country in order to bring the patients received dose for specified radiological procedure to minimum level.