[en] Objective: To compare the diagnostic accuracy of bedside ultrasound and supine chest radiography for the diagnosis of traumatic pneumothorax. Study Design: Analytical study. Place and Duration of Study: PIMS and PAEC General Hospital, Islamabad, from November 2014 to August 2015. Methodology: Patients coming to emergency departments of the study centres, who had sustained chest injuries, were inducted. Their portable bedside ultrasound and supine chest radiographs were taken for assessing pneumothorax and subsequently CT chest was done for confirmation as gold standard. Result: Based on CT findings, sensitivity for ultrasonography and chest radiography was found to be 83.33 percentage and 54.76 percentage, respectively and specificity of 100 percentage for both modalities. Conclusion: Ultrasound can be used as a useful and suitable adjunct to CT in trauma patients as it is easily available, non-invasive, bedside, easily examined with no radiation risk. (author)