This assay showed the different opinions about renal CCDUS and its great role in evaluation of these cases. Also, the technique and approaches of renal Doppler are showed. The different opinions about the optimal site for Doppler sample (proximal and distal / renal artery proper and segmental renal arteries) and the indices which can be used are discussed. All these opinions are supported with the operator’s works and results as a trial to reach the most accurate technique. Any screening tool must rely on clinical preselection. It should be safe, of low cost and high sensitivity or low false positive rate. CCDUS should be the first choice in screening of renal arteries. It becomes easier and more accurate with the great advances of the newly formed machines. Gadolinium enhanced MRA is more superior in definitive diagnosis, preoperative assessment and detection of accessory RAS. With the recent advances in vascular interventions there is increased need to renal CCDUS for non-invasive, easy and accurate follow up. Color Doppler is markedly helpful for the follow up of the renal vessels of the transplanted kidney to detect the most common vascular complications.