CONTEXT : Endemic area and iodine supplementation may affect the pathogenesis of the nodule which commonly occurs in endemic thyroid enlargement due to iodine deficiency. AIMS : To establish pathological changes in solitary solid and larger nodule of the thyroid in endemic area. SETTING AND DESIGN: Retrospective study in Surgical Department of University Hospital. METHODS AND MATERIAL : We determined 44 surgically treated patients with solitary solid nodule in endemic goiter area in which the population routinely receives iodinated salt. The thyroid nodule was preoperatively evaluated with blood chemistry, ultrasound, nuclear scanning and FNAC. The results of preoperative evaluation, surgical interventions, and histopathological examination were analyzed. STATISTICAL ANALYSIS : Student t test and Fisher's exact test. RESULTS: Twenty (45%;20/44) patients with hot (autonomous) nodule have received the diagnosis of toxic adenoma. Twenty four patients had solitary solid and cold nodule. Total thyroidectomy was performed on two patients with papillary cancer (PTC) diagnosed by FNAC from cold nodules. Forty two patients have been treated with total excision of the lobe including hyper or hypoactive solitary solid nodule. Pathological examination has reported two more cases of PTC and one case of insular cancer arising from cold nodules. Completion thyroidectomy was performed on these 3 patients. CONCLUSIONS : Solitary solid and large nodule is a common indication for thyroid surgery in endemic goiter area. High incidence of hyperthyroidism due to single autonomous nodule, and high rate of malignant change (mainly papillary cancer) in solitary hypoactive nodule arises from this series in endemic thyroid enlargement.