Medullary thyroid carcinoma is a rare malignant tumor of the thyroid. An early diagnosis is associated with a better prognosis. Calcitonin is the cornerstone of diagnosis. In this study, we will discuss the clinical and evolutionary characteristics of this condition through a retrospective study of thirty-three patients over a period of seven years between January 2013 and December 2019. Our study includes 33 patients, comprising 12 men and 21 women with a sex ratio of 0.57. The average age of our patients is 45 years. A family history of similar cases was present in six patients (18%). As for the circumstances of discovery in our study, all our patients consulted for a cervical swelling (100%). Seven patients (20%) presented with signs suggestive of malignancy (dysphonia), and fourteen patients (40%) had lymphadenopathy at the time of diagnosis. Calcitonin levels were measured preoperatively in eighteen patients with a very high recurrence rate (60%). Cervical lymph node metastases were present in 40% of cases (fourteen patients). Total thyroidectomy was performed in all patients in our series. It was performed initially in 70% of cases. For patients who initially underwent partial thyroidectomy, we performed totalization regarding the other thyroid lobe. Lymph node dissection was performed in 60% of cases. Radiotherapy was indicated for all patients in our series except for the two patients with normal postoperative calcitonin levels. Close surveillance was the therapeutic choice for these patients. MTC remains a relatively rare tumor. It mainly affects young adults and mainly manifests as an isolated thyroid nodule. It is a lymphophilic tumor, and lymph node involvement is very early. Calcitonin is the basis of preoperative diagnosis. It guides the stage of the disease, helps to guide surgery, constitutes a key element of follow-up, and is considered an important prognostic factor for survival. Despite advances in targeted therapy, complete surgical resection rem