Fine-needle aspiration biopsy of head and neck lesions. The case records of 213 fine-needle aspiration biopsies (FNAB) of head and neck masses performed on 209 patients over a 3-year period were reviewed to assess the diagnostic accuracy and safety of this technique in comparison with surgical histologic examination. Cytologic diagnoses based on FNAB were compared with histologic diagnoses in 110 patients who underwent surgery. Based on cytology alone, 40.3% of the lesions were reported as malignant, 45.1% as benign, and 14.6% as indeterminant. A specific cytologic diagnosis was made in 85.5% of the cases. Cytologic diagnoses concurred with surgical histologic diagnoses 90% of the time. Fine-needle aspiration biopsy was found to have a false-positive rate of 0.5% and a false-negative rate of 2.3%. The sensitivity and specificity of FNAB in determining a malignant diagnosis were 81.1% and 99%, respectively. Positive and negative predictive values were calculated at 98.9% and 82.8%, respectively. Diagnostic rate, sensitivity, and negative predictive value increased consistently throughout the study period, indicating that the diagnostic accuracy of FNAB improved with experience. 