The present investigation was performed to assess the clinical consequences, utility and efficacy of colour duplex sonography (CDS) compared with angiography as a preoperative examination in aorta, pelvis and lower limb, and thus to estimate the cost-effectiveness of CDS. CDS was additionally performed in 53 consecutive patients referred for preoperative angiography of the lower limb. The results for 49 patients were reviewed and compared to assess the technique's clinical utility. The costs of the two methods and the consequences of inappropriate treatment were assessed. In 15 patients inadequate diagnoses were obtained at CDS. If surgery had been performed solely on the basis of the ultrasonographic diagnosis, repeat surgery would have been necessary in 9 patients. In a further 3 patients necessary surgery would not have been performed. Two patients would have been overtreated (unnecessary surgery instead of percutaneous transluminal balloon angioplasty). To correct the initial incorrect diagnosis the estimated yearly cost would be approximately 1.3 million Swedish crowns. In addition, complications and discomfort could be anticipated for the patients. Because of its low sensitivity CDS ist not cost-effective as a preoperative investigation of arteries of the pelvis and lower limb.