BackgroundMass lesions occurring under the oral mucosal epithelium are often small and difficult to diagnose; however, intraoral ultrasonography can delineate these lesions. We aimed to investigate the features of submucosal mass lesions in the oral cavity using intraoral ultrasonography.MethodsFifty patients with hemangioma, irritation fibroma, mucous cyst, lipoma, and pleomorphic adenoma were included. Age, site, largest diameter, thickness, marginal morphology type, border type, internal echo posterior echo, and internal or peripheral Doppler images of the lesions were recorded.ResultsThe hemangiomas were internally hypoechoic and exhibited a cord‐like structure; irritation fibromas, mainly internally isoechoic; mucous cysts, hypoechoic; and the lipomas appeared as homogeneous, isoechoic, or hyperechoic images with unclear borders. Pleomorphic adenomas were surrounded by a single hypoechoic zone, suggesting a thick capsular structure, were predominantly isoechoic internally, and appeared as cyst‐like hypoechoic images.ConclusionsThe features of the lesions were identified and delineated using intraoral ultrasonography.