Introduction. Leiomyoma is a benign vascular tumor affecting the greater saphenous vein rarely. Proper histopathological examination sets the diagnosis after complete and wide surgical excision along with a normal portion of the GSV. Case Presentation. A 36-year-old woman was admitted to our hospital complaining of a dull ache on her right groin for the last three months, along with a palpable mass on the mentioned area. An ultrasound (U/S) scan revealed a solid mass measuring 3 × 2 cm. After wide surgical excision, pathological examination revealed a leiomyoma of the GSV. Discussion. Benign and mostly malignant tumors arising from the GSV are reported in the literature before. Diagnostic modalities and clinical examination cannot set a correct diagnosis preoperatively due to no specific characteristics of these tumors. Possible sarcomatous behaviour has to be kept in mind when treating tumors arising from a vessel wall and wide surgical excision as negative margins should be attempted.