The association between chronic lymphocytic thyroiditis and papillary thyroid carcinoma has been investigated for several years from different perspectives but with few attempts to design a common frame of reference to understand the complex mutual interactions between the various pathways of inflammatory response and of thyroid tumor induction and progression. This article reviews the current knowledge and research on this topic according to epidemiologic, immunobiologic, pathologic, and biomolecular points of view, highlighting achievements and lack of knowledge. It draws some conclusions and points at possible future directions for research. Copyright © 2009 Cognizant Comm. Corp.