At the surgical clinic of the Faculty Hospital in Plzen in 1987-1991 a total of 230 operations of the thyroid gland were performed in 227 patients, incl., 30 operations on account of malignancies in 27 patients. The presented study is focused on malignant diseases. The mean age of the patients was 57.7 years, women predominated. Postoperative complications such as pareses of the recurrent nerve occurred only in one patient. Only one patient died from generalization of thyroid carcinoma. The authors compared the group with a previous clinical study made in 1967-1983 and with the year 1992. In 1992 they proved an increase of benign and malignant thyroid disease.