Background Venous malformations (VMs) are the most common type of vascular malformations. Intramuscular venous malformations (IMVMs) are lesions involving the muscles, excluding intramuscular hemangiomas. The purpose of this study was to compare clinical outcomes between patients with IMVMs who were treated with sclerotherapy and those who were treated with surgical excision.Methods Of 492 patients with VMs treated between July 2011 and August 2020 at a single medical center for vascular anomalies, 63 patients diagnosed with IMVM were retrospectively reviewed. Pain, movement limitations, swelling, and quality of life (QOL) were evaluated subjectively, while radiological outcomes were assessed by qualified radiologists at the center. Complication rates were also evaluated, and radiological and clinical examinations were used to determine which treatment group (sclerotherapy or surgical excision) exhibited greater improvement.Results Although there were no significant differences in pain (P=0.471), swelling (P=0.322), or the occurrence of complications (P=0.206) between the two treatment groups, the surgical treatment group exhibited significantly better outcomes with regard to movement limitations (P=0.010), QOL (P=0.013), and radiological outcomes (P=0.017). Moreover, both duplex ultrasonography and magnetic resonance imaging showed greater improvements in clinical outcomes in the surgical excision group than in the sclerotherapy group.Conclusions Although several studies have examined IMVM treatment methods, no clear guidelines for treatment selection have been developed. Based on the results of this study, surgical excision is strongly encouraged for the treatment of IMVMs.