Introduction. Thyroid cancer (TC) comprises 1% of all carcinomas and is the most common malignancy of the endocrine system. The disease is more common in women, with its peak morbidity in 40-50 year-old patients. The main risk factors include radiation, iodine deficiency, hereditary background and genetic mutations. Among all diagnosed thyroid nodules, 5-30% will evolve into cancer. The gold-standard procedure in the preoperative evaluation of a nodular goiter, apart from ultrasonography, is Fine Needle Aspiration Biopsy [FNA]. The FNA biopsy is favoured for its simplicity, safety, high specificity and sensitivity rates.The aim of our study was to evaluate the clinical efficacy of FNA based on the patients’ register.Material and method. In the Department of Surgery at the 4th Military... Teaching Hospital in Wroclaw, 2,133 patients underwent thyroid surgery for thyroid goiter between 1996 and 2015. 108 cases of TC were diagnosed and from these 66 patients had a preoperative FNA.Results. 14 FNA's (21%) revealed cancer, all of which were confirmed in the postoperative histopathology, although 6 cases of FNA-diagnosed cancer revealed a different histological type postoperatively. 18 FNA's (27%) were suspected of being malignant. A disturbingly high rate of 'benign' FNA biopsies (32 cases – 48%) revealed TC after surgery.Conclusion. It is of the greatest importance to improve the quality of FNA, also due to the wider use of the Bethesda cytological evaluation system. FNA biopsy remains an obligatory and valuable diagnostic tool in thyroid nodules, but it is still insufficient as a standard procedure. A preoperative biopsy should always be related to all the available clinical data in order to provide the best treatment option for each patient individually.