Aim: Thyroid is a suitable organ for the investigation with ultrasonography due to its very superficial localization in body. It is also useful in frequent controls of the organ. The thyroid volume is variable among countries and its value in our country was not clearly demonstrated. In this study we aimed to determine the thyroid volume and its relation with isthmus thickness in Turkey. Method: A total of 251 healthy volunteers were included in the study (105 man, 146 women, age range 15-78. EUB-6000 Hitachi USG device with 10 Mhz lineer probe was used by a dedicated single operator. Craniocaudal length, transverse and mediolateral length (width), antero posterior length for each lobe and isthmus thickness were measured and recorded. Result: Mean total thyroid volume was 13±6.27 ml (man; 15.87±7.18, women; 10.94±4.53, p<0.05). Mean Isthmus thickness was 3.23±1.10 mm (men; 3.42±1.14, women; 3.10±1.05) Total thyroid volume was correlated with height, weight, age, BMI and isthmus thickness. In general all volumes of thyroid gland was bigger in man when compared to women and bigger for right lobe compared to left one. Normal values of thyroid volumes were determined for age groups. Conclusion: Ultrasonography was useful in determination of volumes of the thyroid gland and normal values were different in various countries.