Varicose veins are common problems and there are many ways of treatment starting from life style modification, medications, compression therapy, surgical treatment, endovenous treatment etc. One of the endovenous treatments is sclerotherapy, a method which can be applied to the telengiectasia, reticular veins, and varicose veins. In the past, it was used only for smaller veins but now with the help of ultrasound guidance, it can be used for main truncal veins as well. It destroys the vein endothelium leading to occlusion and subsequent fibrosis of the target vessel. Injection sclerotherapy has assumed a major role in the treatment of venous insufficiency, particularly in the treatment of smaller veins such as telengiectasias and spider veins and smaller diameter tributaries. This is a very important treatment for recurrent veins and it can be combined with various other treatments. In the procedure of sclerotherapy, sclerosant agent is injected in veins. It may be injected direct undiluted, diluted, or in a form of foam. Depending on the type of vein and diameter of vein, different dilutions are used. Though the recurrence with sclerotherapy is high but being a minimal invasive technique with low cost, it is a favorable technique for varicose veins.