Besides the genetic and environmental factors, radiation is an important aetiological cause in the occurrence of thyroid cancer (TC), particularly papillary carcinoma. Chernobyl disaster led to a dramatic increase in the frequency of TC in Eastern Europe. We aimed to determine the data of TC in our unit from 1982 to 2006 and whether Chernobyl disaster has a possible effect on TC distribution. The data of 35 1 patients with TC are reviewed retrospectively. The dates at diagnosis were classified in Five time periods. The ratios of TCs in our unit were concordant with the literature. Comparing the five 5-year periods, there was a significant decrease in the ratio of follicular carcinoma (p<0.01) although the ratio of other thyroid cancers did not change (p>0.05). The ratio of papillary microcarcinoma increased (p<0.01) while the ratio of classical form decreased (p < 0.01). The differences between the time periods and the mean ages at diagnosis for each TCs were not significant (p>0.05). If Chernobyl disaster had any effect, the mean age at diagnosis would be Younger. The decrease in the ratio of follicular carcinoma in our study may be due to iodine supplementation. The higher ratio of papillary microcarcinoma can be related to increased diagnostic scrutiny. Epidemiological Studies are necessary to determine TC incidence in Turkey.