We evaluated the after-hours support that radiologists could provide from their homes to an urban hospital for reading emergency computerized tomography (CT) scans. During a six-month study period, 36 CT scans were acquired using a video-capture card in a PC and transmitted via an ordinary telephone line. The teleradiology interpretation and the formal report (from the hard copy) were compared with a reference or gold standard interpretation made by a radiologist and an emergency physician for 31 of the 36 cases. In comparison with the gold standard, there were 26 correct diagnoses by teleradiology (84%) and five incorrect (16%). Head CT scans accounted for 74% of the transmitted scans and all five of the cases with discrepant diagnoses. The cause of the single clinically relevant discrepancy was found to be unrelated to the use of teleradiology. In comparison with the formal report, the accuracy of the teleradiologist was not significantly different for all categories combined or for head CT scans alone. Video-capture technology provided a reliable means of transmitting CT scans for after-hours interpretation in emergency cases.