The diagnostic accuracy of fine needle aspiration cytology (FNAC) was evaluated in thyroid nodules in 100 consecutive cases, who subsequently underwent thyroidectomy between the years 1989-1991. FNAC as a diagnostic test for thyroid nodules demonstrated an accuracy of 90.9%, a sensitivity of 76.5%, a specificity of 95.9% with a false positivity of 2%, false negativity of 4%, positive and negative predictive values of 86.7% and 92.2%, respectively. A correct classification of the carcinoma type on the basis of FNAC was possible only in 69% patients. As a result, FNAC is the first line of investigation in most nontoxic nodular goiters and often the only procedure necessary to obtain an accurate diagnosis. However, it is recommended only as an adjunct to clinical judgment and is not intended to replace it.