OBJECTIVE To review published evidence concerning treatment of varicose veins using ultrasound-guided foam sclerotherapy (UGFS) to assess the safety and efficacy of this treatment. METHODS Medical literature databases including MedLine, Embase and DH-DATA were searched for recent literature concerning UGFS. Papers describing the early results and later outcome have been assessed and their main findings were included in this summary. RESULTS Few randomized studies have been published in this field and much of the available data come from clinical series reported by individual clinicians. It is clear that foam sclerotherapy is far more effective than liquid sclerotherapy and that ultrasound imaging allows the treatment to be delivered accurately to affected veins. There is evidence that 3% polidocanol foam is no more effective than 1% polidocanol foam. The optimum ratio of gas to liquid is 4:1, although a range of ratios is reported in the published work. There is a wide variation in the volume used as well as the method by which it is injected. The use of carbon dioxide foam reduces the systemic complications, particularly visual disturbance, as compared with air foams. Very few serious adverse events have been reported in the literature despite the widespread use of this method. Rates of recanalization of saphenous trunks following UGFS are similar to those observed after endovenous laser and endovenous RF ablation of veins, as well as the residual incompetence after surgical treatment. CONCLUSIONS UGFS is a safe and effective method of treating varicose veins. The relative advantages or disadvantages of this treatment in the longer term have yet to be published.