Primary thyroid lymphomas constitute up to 5% of all thyroid malignancies and can be divided into non-Hodgkin's lymphomas of B and T cell types, as well as Hodgkin's lymphomas. Recently, mucosa-associated lymphoid tissue lymphoma (MALToma) are recognized as a B cell subset of non-stomach origin. However, they may also occur in lungs, salivary glands, skin, and other sites, including the thyroid. Thyroid MALTomas make up about 9% of all non-gastrointestinal tract tyroid lymophomas. MALTomas are thought to develop from acquired lymphocytic tissue during the course of a chronic inflammatory or autoimmune process. In the thyroid, which is normally devoid of lymphocytic tissues, chronic autoimmune thyroiditis (Hashimoto's disease) has been associated with an increased risk of lymphoma, including MALT type. We report a case of MALToma of the thyroid.