Background: Hashimoto thyroiditis (HT) is an organ-specific autoimmune disease characterized by the production of antibodies such as antithyroperoxidase, which leads to the destruction of the thyroid gland and a decrease in normal thyroid function. Thyroidectomy is performed when the patient presents with symptoms or potential neoplastic degeneration occurs; however, surgery can be difficult because of the dense inflammatory process around the thyroid gland. We hypothesized that patients with HT may have a higher rate of complications after thyroid surgery. Methods: We identified 1791 consecutive patients who underwent thyroidectomy from May 1994 to December 2009. Patients with HT were compared with those without HT with regard to outcomes with analysis of variance and chi-square test (SPSS, Inc). Results: Patients with HT were significantly younger and more likely to be female. There was no significant difference between the two groups in the rate of malignancy. However, patients undergoing thyroidectomy with HT had a significantly higher postoperative complication rate. Specifically, the rates of overall, transient, and permanent complications were all increased in HT patients. Conclusion: Patients with HT had a higher rate of complications after thyroidectomy compared with those without HT. Therefore, careful consideration must be taken before pursuing operative treatment in patients with HT including providing adequate informed consent regarding the increased risks of surgery. © 2012 Elsevier Inc. All rights reserved.