Oncocytic carcinoma of the thyroid (Hurthle cell carcinoma—HCC) has been reported to be associated with a more aggressive clinical behavior compared to other differentiated thyroid cancers (DTCs); with a tendency to higher frequency of metastasis and higher mortality rates. Older age, larger tumor size at diagnosis, extra-thyroid extension (ETE), and higher stage (AMES prognostic index) at diagnosis are considered by many authors to be poor prognostic features with lower survival rates for oncocytic/Hurthle cell carcinomas (HCCs). With the exception of few studies, nodal metastasis was correlated with an adverse prognosis, while distant metastasis always resulted in a poor prognosis with dismal outcome. Extensive surgery, external beam radiation therapy (EBRT), and chemotherapy were also reported as factors that were associated with decreased survival. This chapter discusses the controversies related to prognosis of patients with oncocytic/HCC and provides the recently published (2022) prognostic nomogram to assess both cancer-specific survival and overall survival in patients with oncocytic/HCC.