Aim of this study was to evaluate the effectivity of MDCT-A in the detecting of active bleeding in transplant patients.Between 1999-2006 532 patients underwent renal or liver transplantation. MDCTA was done to the recipients who had decrease in hemoglobine level and/or who were detected to have hematoma during abdominal ultrasound imaging. The MDCT-A was done with 16-detector (Siemens, Sensation) computed tomography (CT) device. 0.75 mm slices in thickness were maintained after injection of non-ionic contrast media at the rate of 4 ml in a second. Multiple ‹ntensity Projection (MIP) technique was used to maintain angiography images in axial and coronal planes. MDCT-A detected active bleeding in 23 posttransplant patients. In these patients 10 were with arterial origin whereas 13 were venous, which were proved either by angiography or during operation. 11 patients underwent angiographic imaging. In 8 of these 11 patients an arterial origin was embolized during angiography. In 3 patients angiographic evaluation was not helpful in finding the bleeding point. 5 of 12 patients who did not undergo angiographic evaluation were followed by clinical and ultrasonographic findings. 7 patients were reoperated. Management of the patients who are suspected to have active bleeding after renal or liver transplantation is very important for the transplant surveys. MDCT-A is a very valuable screening modality in determaining active bleeding as it is an accurate and feasible technique.