This paper attempts to review current opinions on medullary thyroid carcinoma. Histologically described for the first time in 1951 belongs to the endocrine-secreting group of tumours (APUD). It can be sporadic as well as hereditary. The histological classification nowadays is increasingly performed immunohistologically via calcitonin. Clinically the tumour ranges from the very small, but hormonally highly active form, to the aggressive, mostly undifferentiated form. According to this the therapy must be radical. Our study group recommends thyroidectomy and functional neck dissection, followed by radio-chemotherapy. A close interdisciplinary follow up of the patients is necessary. Our surgical department treated 1048 thyroid malignancies between 1949 and 1982. 26 patients (2.4%) were diagnosed to have medullary thyroid carcinoma. Follow up time was between 1 month and 17 years. The recurrence--free interval was 4.5 years. The 5 and 10 year survival rate was 52% and 26%, respectively.