Background The aim of this study was to investigate the changes in vital signs and hemodynamic status that occur in patients during the intraoperative course of thyroidectomy in Graves' Disease (GD). Methods A total of 71 patients were included in the study. Patients were directed to surgery when they had large goiters with compressive symptoms or suspicious nodules, were pregnant or lactating, were unresponsive or intolerant to antithyroid drugs (ATDs), or expressed a preference to have surgery. All patients scheduled for operations underwent surgery while in the euthyroid state. Results Hemodynamic instability was observed in 18 patients during thyroidectomy. Disease duration, sample weight, and thyroid-stimulating hormone receptor antibodies (TRAb) levels were found to be effective on hemodynamic instability. Logistic regression analysis revealed an 11-fold increase in the instability risk in patients with a period of disease shorter than 21 months (P = 0.037). A TRAb value >11.5 increased the risk by 235fold (p < 0.001). Conclusion High levels of TRAb values and new onset of disease with shorter periods of ATDs use may be risk factors for hemodynamic instability during thyroidectomy. Patients with larger thyroid glands are at greater risk for instability during surgery. Those risks should be taken into account during surgery, and the surgical and anesthetic management of the patient should be made more carefully in concordance with the anesthesia team.