OBJECTIVE. The purpose of our study was to assess the efficacy of s commercially available digital teleradiology system in the off-site interpretation of radiologic studies performed in the emergency department. MATERIALS AND METHODS. Over a 6-month period, all radiologic studies performed at Roosevelt Hospital between the hours of midnight and 8 A.M. were digitized and then transmitted over a T1 fiberoptic link to the radiology department of St. Luke's Hospital, 4.6 km away. A total of 829 radiologic examinations were performed, 17 of which were lost to follow-up, leaving 812 studies available for review (693 plain radiographs, 118 CT exams, end one MR imaging study). The preliminary teleradiology interpretations were performed by a resident on duty (with between 1 and 3.5 years of training) using a commercially available teleradiology system (Vortech PDS; Kodak Health Imaging Systems Inc., Dallas, TX) at St. Luke's Hospital. This interpretation was compared with the official film interpretation (which was used as the gold standard) performed within 24 hr by a board-certified attending radiologist at Roosevelt Hospital. All studies with clinically significant discrepant interpretations were redigitized, and the digital images were reviewed by at least two attending radiologists. Side-by-side comparison was made with the original analog examinations to determine the source of the discrepancy. Discrepant images were then graded in conjunction with an attending physician from the emergency department to determine the clinical impact on patient management. RESULTS. Clinically significant discrepancies (those with the potential to affect patient management) in image interpretation were found in 38 cases (5% of the total). Of these 38 cases, three cases (0.4%) were due to an inadequate digital image while 14 (2%) were due to interobserver error. Two (0.2%) discrepancies were due to film reader error, and 19 (2%) were due to digital image reader error. Reasons for inadequate digital images included underpenetrated radiographs and drifting of the laser digitizer. CONCLUSION. Commercially available teleradiology equipment can be both reliably and effectively used for off-hours interpretation of radiologic studies made in the emergency department.