The aim of the study was the evaluation of the occurrence and type of nodular lesions of thyroid gland in the materials of the 1st Department of General and Endocrinological Surgery of Medical University in Białystok from 1993 to 2006.Material and methods. The clinical material was based on 3477 patients that underwent thyreoidectomy for nodular disease in above-mentioned period. Four periods and research groups were established with regard to the character of the goiter according to histopathological examination.Results. The number of thyroidectomies was significantly decreased. There was a increase in the percentage of patients operated for multinodular non-toxic goiter and a significant decrease in the number of patients with multinodular toxic goiter in the whole research group. The percentage of patients that underwent thyroidectomy for mononodular non-toxic goiter was increased as well in women as in men. Mononodular toxic goiter rarely occurred and there was no case of it in men. With a passage of time there was a significant increase in the number of patients operated for papillary cancer as well as for follicular cancer. Medullary cancer and non-differentiated cancer rarely occurred in analyzed material.Conclusions. There was a distinct decrease in the frequency of the occurrence of nodular lesions as well as in the number of thyroidectomies. The profile of thyroid nodules underwent changes in given periods pointing out the lower frequency of toxic goiter and the higher frequency of neoplasmatic lesions in the third and particularly in the fourth research period.