Background: The chest radiograph is considered one of the most complex imaging modalities to interpret. Several studies have evaluated radiograph interpretation in the emergency department, and considerable disagreement among clinical physicians and expert radiologists has been observed in the reading of chest films. The interpretation of chest radiographs by emergency department physicians was compared with senior radiologists in discharged patients, and misinterpretations assessed in relation to the physician's level of training. Methods: Radiological descriptions of 509 chest radiographs of 507 patients, aged 16-98 years who were discharged from the emergency department, were prospectively reviewed. Missed findings were recorded with regard to the physician's level of training and experience. The effects of misinterpretations on discharge recommendations were also investigated. Statistical assessment was conducted using the χ2 test. Interobserver agreement was also tested by the κ coefficient. Results: The sensitivity for detecting different abnormalities in the radiographs ranged from 20% to 64.9% and specificity from 94.9% to 98.7%. Despite the low sensitivities found, there were relatively few clinical implications of the "missed" findings since they were either of a minor nature or appropriate follow up was prescribed. The overall interobserver reliability, assessed by the κ coefficient, was 0.40 (95% confidence interval 0.35 to 0.46). These findings did not change significantly by emergency department physician's level of training. Conclusions: Emergency department physicians frequently miss specific radiographic abnormalities and there is considerable discrepancy between their interpretations and those of trained radiologists. These findings highlight the importance of routine evaluation of chest radiographs by a well trained radiologist and emphasise the need for improving interpretive skills among emergency department physicians.