Introduction: High‑resolution ultrasonography (USG) is the most sensitive imaging modality available for examination of the thyroid gland and associated abnormalities. Ultrasound scanning is non‑invasive, widely available, less expensive, and does not use any ionizing radiation. In pathological conditions such as Graves’ disease, thyroid enlargement and hyperfunction are accompanied by a markedly increased blood flow. As mentioned in the 2011 ATA (American Thyroid Association) guideline, the Color Doppler Flow Sonography (CDFS) of thyroid, as an indicator of thyroid blood flow status, has some practical values in the differentiation of thyrotoxicosis. This study intends to find doppler indices of superior thyroid arteries (STAs) and compare between euthyroid and abnormal thyroid functional state subjects. Aims and objectives: To find the doppler indices of superior thyroid artery and compare it between euthyroid and abnormal thyroid functional state individuals. Materials and methods: This hospital based prospective observational study was conducted by including 50 patients of different age groups and from both sexes. Study was conducted in the Department of Radiodiagnosis, Muzaffarnagar Medical College, Muzaffarnagar, U.P. Duration of the study was for eighteen months (April 2019 to Sep 2020). After explaining the entire radiological procedure to the patient, informed consent was obtained. A detailed clinical history was recorded. B scan of thyroid gland was performed using ultrasonography machine - Alpinion Ecube8 with 7-12 MHz linear probe. Subsequently, superior thyroid artery was identified and doppler scan was performed. Results: This study included 50 subjects in total. Most of the cases were in the age group of 21-30 years (44%), 2nd largest were in the group of 31-40 years (26%) and smaller numbers were in the age group of 11-20 years (10%), 41-50 years (12%) and 51-60 years (8%). Out of 50 subjects studied, 5 males (10%) and 22 females (44%) were hyperthyroid; 1 male (2%) and 7 females (14%) were hypothyroid; 6 males (12%) and 9 females (18%) were euthyroid. There were no significant differences in the descriptive statistics of parameters (mean ± SD) between the right and left STAs: PSV (49.76 ± 23.95 vs 51.22 ± 25.99 cm/s, p = 0.06), PI (0.86 ± 0.08 vs 0.86 ± 0.08, p = 0.89) and RI (0.60 ± 0.03 vs 0.61 ± 0.04, p = 0.10). The average PSV of bilateral STAs was significantly higher in patients with hyperthyroidism than in those with euthyroidism: PSV (21.12 ± 1.82 vs 73.14 ± 4.33 cm/s, p = < 0.01), PI (0.57 ± 0.03 vs 0.92 ± 0.04, p = 0.01) The average RI value was higher in patients with hyperthyroidism than in those with euthyroidism, but the differences were not significant RI (0.57 ± 0.03 vs 0.63 ± 0.03, p = 0.34). The average PSV, PI and RI values of bilateral STAs were higher in patients with hypothyroidism than in those with euthyroidism but they were not very significant: PSV (21.12 ± 1.82 vs 24.17 ± 2.49 cm/s, p = 0.72), PI (0.76 ± 0.03 vs 0.81 ± 0.03, p = 0.07) and RI (0.57 ± 0.03 vs 0.61 ± 0.03, p = 0.82). Summary and Conclusion: In conclusion, CDU (PSV, PI, RI) parameters do not differ significantly between the right and left lobes of the thyroid gland. PSV is useful for evaluating thyroid functional status to differentiate hyperthyroidism from euthyroidism but RI showed considerable overlap in values between euthyroid and hyperthyroid patients. CDU parameters (PSV, PI, RI) did not show any significant difference between euthyroid and hypothyroid patients. Since there is no significant difference in CDU parameters between the right and left STAs, we propose that parameters of one side can be used to evaluate the clinical condition of patients with thyroid disorders.