20 patients (i.e. 40 lower extremities) with chronic venous insufficiency were examined by means of colour-coded Doppler sonography (CCDS). This method enables the simultaneous visualisation of the anatomy and haemodynamics of the examined vessels. All cases of varicosis of the stem of the vena saphena magna (VSM) (n = 21) and of the vena saphena parva (VSP) (n = 13) were correctly diagnosed by CCDS. However, an incomplete varicosis of the stem was identified in only 3 of 5 cases. Insufficiency of the V. perforantes was identified by CCDS with a high rate of accuracy in diagnosing the insufficiency of the cross of the VSM and VSP. Although assessment of the V. perforantes and diagnosis of incomplete stem varicoses or varicoses of lateral branches is possible, as a rule, it does take up much time and requires a great deal of experience on the part of the investigator.