Gastrointestinal leiomyosarcoma remains relatively rare,accounting for only 1% of gastric tumors,since the use of c-kit staining was first described in 1998 to differentiate gastrointestinal stromal tumors.In this case report,we described the clinical manifestations,endoscopic features, and pathological immunohistochemical features of the gastric leiomyosarcoma.We found that endoscopic ultrasonography has great value in the diagnosis of gastric leiomyosarcoma,and that minimally invasive endoscopic treatment is safe and effective.Particularly,this case highlights that the early-stage lesions can be treated with minimally invasive endoscopic treatment with good tolerance and satisfactory clinical results.Endoscopic submucosal dissection is thus effective for treating gastric leiomyosarcoma,with promising prospects for clinical application.