Objectives: To investigate the role of MMP-2 and TIMP-2 in the invasion and metastasis of thyroid papillary microcarcinomas. Materials and Methods: We performed immunohistochemical study on MMP-2 and its tissue inhibitor (TIMP-2) using tissue microarrays containing 2 cores of 40 microPTC and 8 non-neoplastic thyroid tissue. The expression intensity was semiquantitatively scored as -, ${pm}$, +1, +2, and +3. Results: Both MMP-2 and TIMP-2 expression was observed in all tumors(100%) and in 1 of 8 non-neoplastic tissue(12.5%), and the positive staining was restricted to the epithelial cells. In 17 and 23 tumors with or without extrathyroid invasion, respectively, 8(47%) and 10(43%) cases showed moderate to strong(+23) positivity for MMP-2. TIMP-2 expression was moderate to strong in 13 cases(76%) and 16 cases(70%) in each group. In multifocal and solitary tumors, 3 of 6(50%) and 11 of 21(52%) cases showed moderate to strong MMP-2 expression, and 5/6(83%) and 15/21(71%) showed moderate to strong TIMP-2 expression. Conclusion: There is no relationship between MMP-2 or TIMP-2 expression and extrathyroid invasion or tumor multifocality in papillary microcarcinoma of the thyroid gland.