Objective: To evaluate duplex or colour flow duplex ultrasound scanning (CFDS) in varicose vein surgery as a perioperative guide for mapping, marking and local anaesthesia (LA), on the basis of our experience since 1990. Design: Retrospective clinical series. Patients and methods: A total of 3150 interventions for varicose veins were performed on an outpatient basis since 1990. This review of the last 4 years' experience (January 1996 to December 1999) deals with 1824 operations (457 men, 938 women; mean age 55.3 years). Duplex scanning or CFDS was used for perioperative investigation in all the patients, but also to guide skin marking and to help in the injection of LA (mepivacaine chloridrate 0.25–0.4%). The surgical approach varied according to the patient's morphohaemodynamic findings. Results: Several different preoperative patterns of varicose vein disease resulted in a ‘made-to-measure’ surgical approach, allowing segmental saphenous stripping in 99.9% of the patients, and ligation of perforating veins in 0.9% of cases. Immediate postoperative walking was possible in 99.8% of the patients and 3–6 h hospitalisation time in 99.5%. LA caused only minor complications (haematoma, urticaria) in 15 cases. Duplex monitoring of infiltration has facilitated LA usage, decreasing the doses and concentrations required and improving its efficacy. The operation costs decreased with time; major complications were 2 deep vein thromboses, one with a probable pulmonary embolism. Conclusion: The use of duplex scanning or CFDS in varicose vein surgery has permitted accurate preoperative evaluation and a guide to injection of LA, resulting in more conservative and targeted surgery. Patient compliance and cost-efficacy were also improved.