We have analysed the results of surgical treatment for microcarcinoma of the thyroid (MCT). In sixteen patient clinical and follow-up data were retrospectively evaluated during a 35.1-month follow-up. Thyroid hyperfunctional state us was present in two subjects. A single nodule was detected by echotomography in 11 patients, while multinodular diffuse goitre was revealed in 3 patients. In the last two subjects, thyroid gland appeared completely normal at ultrasonography, despite laterocervical lymph node metastases. Fine-needle aspiration biopsy was performed in 6 patients and its diagnostic accuracy was high (83,3%). MCT was classified as "incidental" in 12 patients and "occult" in the remaining 4 patients. Eight subjects underwent total thyroidectomy and 8 hemithyroidectomy plus isthmectomy. No postoperative complications were recorded. In 10 patients MCT histotype was papillar adenocarcinoma, in 5 was follicular adenocarcinoma and in the remaining case it was medullary carcinoma. Goitre was associated in 75% of the cases. Only in a patient disease progressed to death because of hematogenous metastases. In conclusion, we believe that incidental MCT is a low-grade malignancy with a benign biological behaviour. Occult MCT is a potentially lethal disease. We did not observe differences in the long-term results between different surgical treatments of MCT.