Objective The aim of this study was to evaluate the contribution of ultrasonography in the establishment of the diagnosis of nonspecific nodular lesions of the oral soft tissues. We determined the indication of use and reliability of ultrasonography in the field of dentistry, considering whether it was of value in the conclusive diagnosis of these pathologies. Materials and Methods We recruited 65 patients from the Oral Medicine Unit of São Lucas Hospital, who had submucosal and subcutaneous nodules, without established diagnosis. They were subjected to ultrasonography of the lesion, carried out with standardization of the protocol and equipment, utilizing a Doppler system. The ultrasonographic report was prepared by an experienced professional, noting the imaging characteristics as well as the possibility of diagnosis. Two calibrated examiners analyzed the data, comparing the ultrasonographic report with the final diagnosis. Accordingly, we used established scoring, where zero corresponded to no contribution to the final diagnosis, 1 helped in the management of the case, and 2 when imaging determined the diagnosis. Results A zero score was obtained for 12.3 % of the examinations performed, and 1 and 2 accounted for respectively 41.5 and 46.1 %, totaling a contribution of about 88 %. Ultrasonography was of value in the diagnosis of vascular lesions in 93.3 % and of neoplasms in 87.5 %. In the salivary gland diseases, it contributed to the final diagnosis in 75 %. Conclusion The results demonstrated that ultrasonography is an effective tool in the determination of the definitive diagnosis of nonspecific nodular lesions of the soft tissues of the oral and maxillofacial region.