Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 49 4 2011 04 15 262 264 EN Ismet Ozaydin Department of General Surgery, School of Medicine, Duzce, Trukey. Cigdem Ozaydin Department of Microbiology and Clinical Microbiology, Ataturk Government Hospital, Duzce, Turkey. Sukru Oksuz Department of Microbiology and Clinical Microbiology, Ataturk Government Hospital, Duzce, Turkey. Mustafa Yildirim Department of Clinical Microbiology and Infectious Disease, School of Medicine, Duzce, Turkey. 2015 09 28 Echinococcosis, although eradicated in many countries, is still widespread in communities where agriculture is dominant. Cystic hydatidosis is a significant public health problem in the regions with endemic echinococcosis. The hydatid cysts tend to form in the liver or lung, but may also be found in other organs of the body such as brain, heart, and bone, while thyroid gland involvement is rather rare. A 25 year old male presented with solitaire goiter. Laboratory tests and thyroid profile proved normal. Surgical exploration revealed hydatid cyst in the left lobe of the thyroid gland. Examination of the nodule showed it to be a solitary primary thyroid hydatid cyst. https://acta.tums.ac.ir/index.php/acta/article/view/3735 https://acta.tums.ac.ir/index.php/acta/article/download/3735/3710