Fifty-one patients treated by total thyroidectomy plus nodal neck dissection of necessity for medullary thyroid carcinoma (MTC) with a minimum follow-up of 10 years (mean 14.5, max 22 years) were divided into three groups according to the outcome (alive disease-free; alive with disease; dead) and were compared in order to analyze the prognostic factors of MTC. Twenty years actuarial survival rate for age at diagnosis less than 50 years versus age over 50 (90% vs 45%) as well as for stage II versus stage III (85% vs 55%) was statistically different (p < 0.005 and p < 0.05 respectively). About 60% of recurrences were observed within 5 years after surgical treatment. Recurrence rate for stage III (70%) versus stage II (20%) was statistically different, but it was not for the age. Survival rate for patients with bony metastases (50% at 1 and 30% at 3 years) versus patients with other than bony metastases (100% at 10 years) was statistically different.