Early diagnosis of thyroid cancer is difficult because the neoplasm coexists or develops against the background of thyroid nodulo-inflammatory pathologies, which have a slow evolution. The association of thyroid carcinoma with autoimmune thyroiditis remains debatable. In the literature, this combination is noted on average from 1% to 75% of cases. In recent years, there has been an increasing trend in the number of cancers of the thyroid gland against the background of autoimmune thyroiditis. The epidemiological features and morbidity of thyroid cancer associated with lymphocytic (autoimmune) thyroiditis in the Republic of Moldova are not fully elucidated.