Thyroid fine-needle aspiration biopsy is the best diagnostic test available for the evaluation of the thyroid nodule. In 2009, the Bethesda system for the cytomorphologic stratification of thyroid cytopathology, was established. In it, 6 categories carry a defined risk of malignancy. The Bethesda system was revised in 2017. The six categories remained, but there were some modifications mainly due to the reclassification of the encapsulated follicular variant of papillary carcinoma (VFCP), which is now called Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). This reclassification changes the risk of malignancy for some of the Bethesda categories. Molecular biology testing is suggested in indeterminate cases.