Color-coded image-directed Doppler sonography (CCIDS) was used in the follow-up of self-expandable vascular endoprostheses and was compared with the results of digital subtraction angiography and Doppler pressure indices. The stents were implanted in iliac and femoral arteries or hemodialysis fistulae of 26 patients. The aim of the study was to evaluate the potential of the new imaging method to identify local flow patterns inside of vascular endoprostheses. The stents were identified by sonography in all cases; laminar flow was represented in CCIDS by homogeneous Doppler signals. In case of a distinctly reduced lumen, intravenous digital subtraction angiography (DSA) and CCIDS were both able to identify the stenotic process; however, CCIDS was superior in the demonstration of minute flow irregularities. No different flow patterns were detected in comparing recent with older vascular implants.