Background: Veins have one-way valves that prevent blood from backing up into the legs when we stand or sit. When the valves become incompetent [or begin to have reflux], blood pools and causes an increase in pressure in the leg veins. Leg veins become enlarged and twisted. Aim of the work: The aim of the current study was to evaluate safety and efficacy of ultrasound guided foam sclerotherapy for the treatment of primary varicose vein. Patients and methods: The current trial is a prospective observational cohort study. It had been carried out at Al-Azhar University Hospital [New Damietta], Egypt. It included Fifty patients who had great saphenous vein [GSV] reflux associated with saphenofemoral junction [SFJ] incompetence. They had been offered foam sclerotherapy as an alternative to standard surgical treatment or conservative management. The duration of the study extended between November 2019 to January 2020. Results: results revealed that post intervention; duplex assessment revealed a radiologic success with complete obliteration of GSV and collaterals in 40 patients [80%]. six patients [12%] underwent direct re-injection for further one or two injection sessions over the following two weeks until complete occlusion of GSV and collaterals was obtained. Conclusion: Foam sclerotherapy is effective & safe in treatment of primary varicose veins.