Background: Demographic disparities have been described for survival after thyroid cancer surgery using national registries and databases. At the institution level, we hypothesized that assessing survival after thyroid cancer surgery in a long-term cohort with diverse gender and racial groups would reveal disparities in survival. Methods: We examined medical records of patients with papillary or follicular thyroid cancer undergoing thyroidectomy, lobectomy, and other surgical procedures from 1971 to 2016 at a tertiary referral center. We obtained information on demographics, cancer stage, procedure, and radioactive iodine (RAI). We measured survival using Kaplan-Meier estimates and Cox proportional hazards models. Results: A total of 1440 (91%) patients with papillary cancer and 144 (9%) patients with follicular thyroid cancer underwent total thyroidectomy (1297, 82%), lobectomy (261, 16.5%), and other surgical procedures (26, 1.5%). Most patients (1131, 71%) were woman, and 909 (57%) were older than 45 years. Race/ethnicity included 805 (51%) white, 161 (10%) African Americans, and 618 (39%) other race/ethnicities. Both 10- and 20-year survival rates in nonwhite males were worse compared with nonwhite females (P <.0001). After controlling for age, cancer type, stage, surgical procedure, RAI, and year of surgery, nonwhite males had a higher mortality risk compared with nonwhite females (P =.0376, confidence interval (CI): 1.03-2.43), white males (P <.0001, CI: 1.88-6.54), and white females (P <.0001, CI: 3.31-9.90). Conclusions: Our diverse cohort demonstrates significant gender and racial disparities in survival after thyroid cancer surgery. To improve health outcomes and reduce health disparities among nonwhite males, interventions and long-term care management should target potentially modifiable causes of worse outcomes in this group.