The aim of clinical practice guidelines is to provide physicians with the best available evidence on particular issues and recommendations for the best standards of care. They help health professionals weigh the benefits and the risks of available diagnostic or therapeutic options. With specifically tailored treatments becoming commonplace, it is important to consider each patient with thyroid cancer individually. Additionally, it is important to note that while a number of different groups have put forth guidelines for the management of thyroid surveillance and cancer therapy, there is some controversy among guidelines regarding certain situations, which has raised concerns about the effects on patient management and outcome. This chapter largely refers to guidelines for diagnosis and management of thyroid cancer including oncocytic carcinoma of the thyroid (Hurthle cell carcinoma—HCC), from the following organizations and the following classification systems: American Thyroid Association (ATA), National Comprehensive Cancer Network (NCCN), European Society for Medical Oncology (ESMO), American Association of Clinical Endocrinologists/Associazione Medici Endocrinologi/European Thyroid Association (AACE/AME/ETA), European Thyroid Association (ETA), Bethesda System for Cytopathology (2023), American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS), and the 2022 World Health Organization (WHO) Classification of Thyroid Neoplasms. Finally, this chapter will provide concluding remarks and recommendations, as well as future perspectives to provide physicians with the best available evidence on particular issues and recommendations for the best standards of care of patients with thyroid cancer, with emphasis on oncocytic/Hurthle cell carcinoma.