Background: The thyroid is the large, single and usually asymmetric endocrine gland consisting of two lateral lobes joined by the isthmus. A thyroid volume over 18 ml in females and 25 ml in males is called goiter. Among the methods evaluating the volume of the thyroid we can submit ultrasonography (US) and scintigraphy (SPECT). The aim of the study was to estimate the volume of goiters by means of US and ^{99m}Tc-SPECT. Material/Methods: A group of 80 patients were examined. Patients were divided into two groups. Group A contained 50 patients (43 females, 7 males) with goiter, where the volume of the thyroid was compared with the use of US and ^{99m}Tc-SPECT. Group B contained 30 patients (23 females, 7 males) with a normal volume of the thyroid gland as shown by US and ^{99m}Tc-SPECT. US of the thyroid gland was made by means of the ALOKA SSD 500 device, with a linear head of 7.5 MHz. ^{99m}Tc-SPECT was made by means of a one head gammacamera Diacam with a low energy high resolution collimator (LEHR). Results: In both groups similar results were obtained. In the group A, the average volume of the goiter was 29.83 ml in US and 33.27 ml in SPECT (p<0.001). In the control group B the average volume of the thyroid gland was 16 ml and 18.18 ml (p<0.001), respectively Conclusions: The thyroid volume estimated by ^{99m}Tc-SPECT was significantly higher than that by US, in both investigated and control groups, and in females and males.