Submucosal lesions (SML) include a diverse array of benign, potentially malignant, andmalignant lesions. The majority of SML’s are asymptomatic and found incidentally. Endosonography (EUS) is the key investigation for these lesions. Although, the morphologic appearance of a SML as seen on EUS is rarely diagnostic, the differential diagnosis can be narrowed down. Obtaining a tissue diagnosis is often necessary, and EUS-FNA and EUSguided trucut biopsy of a SML can be carried out. Information about the malignant potential, layer or origin, size, and extramural extension of an SML is also provided by EUS. EUS is strongly indicated before endoscopic or surgical resection of any SML. The most commonly encountered SML’s in the upper gastrointestinal tract are GIST’s, leiomyoma’s, neuroendocrine tumors, lipomas, granular cell tumors, varices, duplication cysts, heterotopic pancreas, Brunner’s gland hamartoma, lymphangiomas. A large number of rare lesions are also seen. This review describes the histological, clinical, endoscopic, and endosonographic appearance of the different SML.