Background: Thyroid cancer is considered the most frequently malignancy of head and neck. Most of the primary thyroid neoplastic are of epithelial origin. Forming the papillary cancer from 75% to 90% of all thyroid cancers. On the other hand medullar, follicular and anaplasic carcinomas constitute altogether only from 10% to 25% of all thyroid carcinomas. The diffusion of high definition ultrasound and the growing availability and using biopsy through the fine needle aspiration (FNBA) have made easier, modified and improved the management of thyroid lesions. Material and methods: A retrospective, descriptive study was made in the period from September 2007 to August 2010 in Oncological Radiology Service of the Instituto Nacional de Cancerologia, where they were analyzed the sonographic features of 44 subjects with a proven diagnosis by cytopathological study obtained by FNAB, or histopathological by means of surgery. Results: Regarding the ultrasonographic features, the predominant variables were, the heterogeneous ecostructure, hypoechogenicity, ill-deined margin, lack of microcalciications, central vascularity, and a higher than wider injury in those injuries with malignant potential. Conclusion: The high resolution ultrasound is an useful tool for the characterization of no papillary thyroid tumors. Surgical resection of the nodule is recommended before the cytopathology report of follicular neoplasia, if there is ultrasonographic suspicion upon malignancy due to lack of discrimination between adenoma and follicular carcinoma.