To investigate the clinicopathological features, therapeutic strategies, and prognostic factors of anaplastic thyroid carcinoma (ATC). Methods A retrospective analysis was conducted on 64 patients with pathologically confirmed ATC treated at The First Affiliated Hospital of Zhengzhou University between January 2012 and January 2025. Clinical data included age, sex, symptoms, laboratory tests, tumor characteristics, metastasis, immunohistochemical markers, and treatment modalities. Survival was estimated by the Kaplan-Meier method, group differences were compared using the log-rank test, and independent prognostic factors were identified by the Cox proportional hazards regression model. Results A total of 64 patients were enrolled, including 23 males (35.9%) and 41 females (64.1%), with a median age of 69 years and a median survival of 6.0 months. The 6-month, 1-year, and 2-year survival rates were 45.4%, 26.2%, and 18.7%, respectively. Univariate analysis showed that age ≥60 years, white blood cell count ≥10×10⁹/L, maximum tumor diameter ≥6 cm, extrathyroidal invasion, cervical and lateral neck lymph node metastasis, distant metastasis, advanced tumor stage, surgical treatment, radiotherapy, chemotherapy, and multimodal therapy were significantly associated with prognosis (P<0.05). Multivariate analysis revealed that age ≥60 years (HR=2.724, 95%CI: 1.155-6.425, P=0.022), lateral neck lymph node metastasis (HR=3.630, 95%CI: 1.619-8.136, P=0.002), and distant metastasis (HR=3.902, 95%CI: 1.969-7.732, P<0.001) were independent risk factors. Radiotherapy (HR=0.307, 95%CI: 0.134-0.703, P=0.005), chemotherapy (HR=0.435, 95%CI: 0.214-0.887, P=0.022), and aggressive multimodal therapy (HR=0.240, 95%CI: 0.120-0.481, P<0.001) were independent protective factors. Conclusion ATC carries an extremely poor prognosis. Age ≥60 years, lateral neck lymph node metastasis, and distant metastasis are independent adverse prognostic factors. Multidisciplinary multimodal treatment, particularly regimens including radiotherapy and chemotherapy, can significantly improve prognosis and provide important guidance for clinical decision-making.