Objective: Medullary thyroid carcinoma (MTC) is an aggressive neuroendocrine tumor affecting the parafollicular C cells of the thyroid gland. This study aimedto analyze demographic and clinical factors that might affect the prognosis of MTC andevaluate the long-term outcomes of surgery in MTC patients at a single center. Material and Methods: A total of 36 patients with a confirmed MTC diagnosis based on histopathological examination and underwent surgery-during 2000-2015 were examined. Archived files of these patients were reviewed, and data on clinical, biochemical, and radiological test results were assessed. Factors affecting disease-free survival were also evaluated. Results: Theduration of the follow-up of the patients was 80.3 +/- 76.1 months. MEN2A was detected in three patients (8.3%). Twelve patients (33.3%) had metastasis at the time of diagnosis. During the follow-up period, local recurrence was observed in 13 (36.1%) patients. Nine patients (25%) presented metastasis at follow-up. The mean disease-free survival was high in sporadic MTC compared to hereditary MTC. Conclusion: The study observed asignificant contribution to the hereditary nature of the disease on prognosis. However,other prognostic factors such as gender, nodule characteristics, recurrence and metastasis, and treatment modalities did differsignificant. Patients with MTC should be evaluated to know if the disease is sporadic or hereditary. The small sample size in this study restricts the power of statistical analysis;therefore, further prospective studies are necessary to reveal the other contributory prognostic factors in MTC.