Thyroid cancer is a comparatively rare tumor, which affects 1-5% of women and approximately 2% of men, although it is the most common endocrine malignancy worldwide. Furthermore, the incidence of thyroid cancer has been increasing remarkably in the last decades. Currently, diagnosis of thyroid cancer mainly is based on cytological criteria. Although fine needle aspiration is a minimally invasive procedure, complications can occur. Correct diagnosis is mandatory to select patients for surgical intervention and to determine appropriate extent of operation. Overdiagnosis and the associated unnecessary surgery should be avoided as it might also lead to complications. Therefore it is important to practice noninvasive methods not only for early diagnosis of thyroid cancer but also for estimation of prognosis. Liquid biopsy is a promising, noninvasive method that can provide detection of circulating tumor cells (CTCs) as well as circulating nucleic acids such as DNA, mRNA, and microRNA in a blood sample. The aim of the chapter is to highlight the efficacy of liquid biopsy for diagnosis and prognosis of thyroid cancer. The chapter will represent a comprehensive literature review based on recent PubMed publications (mainly 2012-2018).