A recommendation for the reporting of thyroid cytological specimens was made as the consensus of the expert meeting arranged by the U.S. National Cancer Institute (NCI). This Bethesda system will replace the former Papa classes also in thyroid cytology. The new Bethesda classification considers the representativeness of the thyroid specimen, and the classification is based on the correlation of the underlying histological change with the cytological report. In particular, follicular tumors and suspicion of them are separated from other tumors into their own group. The new system will bring about a significant improvement to the reports of thyroid cytological specimens.