'Submucosal tumors' represent a bulge underneath the mucosa of the gastrointestinal tract whose etiology cannot be determined by gastrointestinal endoscopy or barium studies. Because many of these lesions do not arise from the submucosa, these abnormalities have been recently referred to as subepithelial lesions. The aim of this review was to assess the value of EUS for the diagnosis and management of suspected subepithelial lesions. Endoscopic ultrasound (EUS) is currently considered the investigative procedure of choice when a subepithelial lesion has been detected. EUS can determine the intra- or extramural location of the lesion, can differentiate vascular, cystic and solid lesions, and can characterize the layer(s) of origin or ultrasound characteristics (size, borders, homogeneity, anechoic areas or echogenic foci). EUS cannot differentiate exactly between benign and malignant tumors, but it can guide fine needle aspiration (FNA) biopsy or histologic needle biopsies, thus providing samples for cytology or histological analysis. EUS also offers valuable information on the clinical management, and helps to decide whether a lesion should be consequently followed, removed by endoscopy or by surgery. The introduction of EUS and endoscopic submucosal resection (ESMR) clearly changed the management of small subepithelial lesions (less than 3 cm). A clinical decision algorithm was subsequently developed, taking into consideration the information offered by most of the reviews and case reports. However, further prospective studies will have to establish the value and indications of ESMR (used in association with EUS), for the treatment of subepithelial lesions, as compared to surgery and follow-up.