The role of FDG PET CT in thyroid malignancy is not clearly established. Malignancy of the thyroid remains poses issues very different from the squamous carcinomas of the upper aerodigestive tract where PET-CT is usually used. Though this is the most common endocrine malignancy, many a times it is difficult to diagnose malignancy in thyroid nodules. The biology of well differentiated thyroid cancer, medullary carcinoma, poorly differentiated carcinoma and anaplastic carcinoma varies significantly and management strategies differ dramatically. FDG PET can be used as a wonderful tool in thyroid malignancy for selected indications.