This chapter provides detail description of FNAC in lesions of thyroid gland. Chapter has 17 well illustrated diagrams and pictures. Indications of FNAC of thyroid lesions, classification of thyroid lesions, nodular colloid goitre, hyperplastic nodule, thyroiditis, follicular neoplasm, hurtle cell neoplasm, papillary carcinoma, immunocytochemistry, lymphomas and metastatic malignant tumors are described in detail with the help of excellent illustrations and histopathological pictures. All salient features of different lesions are highlighted in 15 boxes. 3 tables are included to provide details of classification of thyroid lesions, differential diagnosis of lesions with follicular pattern and Hurtle cell tumors for easy learning. 40 references are included at the end of the chapter to facilitate further reading.