Background: Fine-needle aspiration (FNA) is accurate in diagnosing papillary, medullary, and anaplastic thyroid cancer, as well as lymphoma. Although many surgeons routinely perform FNA before surgery, some question whether FNA influences operative management. Therefore, to determine whether FNA affects surgical management in patients with thyroid cancer, we reviewed our experience. Methods: A total of 442 consecutive patients underwent thyroid surgery at 1 academic center. Of these, 411 had surgery for an index nodule in the absence of previous radiation or familial thyroid cancer. FNA, operative, and permanent histology findings were reviewed. Results: The average patient age was 46 years, and 79% were female. A total of 211 patients (51%) had a preoperative FNA, and 71 (17%) had a final diagnosis of cancer. The sensitivity and specificity of FNA for thyroid cancer were 89% and 92%, respectively. In the FNA group, 1 (2.4%) of 41 patients with papillary thyroid cancer required completion thyroidectomy. In contrast, in the no-FNA group, 4 (40%) of 10 patients with papillary thyroid cancer required a second operation. No patient in the FNA group received thyroid resection for lymphoma, whereas three (100%) of three patients with lymphoma in the no-FNA group were treated surgically. A total of 98% of the FNA group, compared with 54% of the no-FNA group, received optimal surgical treatment for thyroid cancer. Conclusions: FNA is a sensitive and specific test for the diagnosis of thyroid cancer, allowing definitive initial surgery and avoiding unnecessary procedures. Therefore, we recommend routine use of preoperative thyroid FNA, even in those patients in whom a resection is already planned. © 2006 The Society of Surgical Oncology, Inc.