Objective: Medullary thyroid carcinoma (MTC) is an aggressive neuroendocrine tumor affecting the parafollicular Ccells 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 surgeryin MTC patients at a single center. Material and Methods:A total of 36 patients with a confirmed MTC diagnosis basedon histopathological examination and underwent surgeryduring 2000–2015 were examined. Archived files of thesepatients 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±76.1months. 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 wasobserved 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 contributiontothe hereditary nature of the disease on prognosis. However,other prognostic factors such as gender, nodule characteristics, recurrence and metastasis, and treatmentmodalities did differsignificant. Patients with MTC should beevaluated to know if the disease is sporadic or hereditary.The small sample size in this study restricts the power ofstatistical analysis;therefore, further prospective studies arenecessary to reveal the other contributory prognostic factors in MTC.