Introduction: Although the prevelance of thyroid nodules is high, the rate of malignancy in these nodules is low. Thus, the distinction between the malignant nodules requiring surgical approach and the benign ones is very important. Ultrasound, ultrasound guided fine needle aspiration and also The Bethesda Reporting System for Thyroid Cytopathology are useful tools for interpretation of thyroid nodules. However, this system includes a problematic category titled as 'Atypia of Undetermined Significance/ Follicular Lesion of Undetermined Significance (AUS/FLUS)'. The reported percentages of malignancy in these nodules range between 5-96,7%, recently. We aimed to present the rate of malignancy in thyroid nodules with initial fine needle aspiration diagnosis as AUS/FLUS. Methods: The final diagnosis (fine needle aspiration and thyroidectomy) of patients who presented at the Department of Pathology of the Trakya University Medical Faculty (Edirne, Turkey) were reviewed for seven years. Results: Histological diagnosis was papillary thyroid carcinoma in 68 (44,4%), follicular carcinoma in 1 (0.7%) and medullary carcinoma in 1 (0.7%) of the 153 patients with prior fine needle aspiration diagnosis as AUS/FLUS. Discussion and Conclusion: Although, The Bethesda Reporting System for Thyroid Cytopathology have provided standardisation in some of categories, the category of AUS/FLUS remains to be including subjective cytological criteria and subsequent malignancy rates are highly variable in different reports. So, ancillary tools such as immunocytochemistry and particularly molecular tests may be appropriate in preoperative diagnosis of thyroid nodules.