OBJECTIVE. The purpose of our study was to reduce the rate of insufficient specimens from fine-needle aspiration cytology (FNAC) of impalpable mammographically detected breast lesions. SUBJECTS AND METHODS. Our previous rate of insufficient specimens for FNAC was 27%. We implemented the following strategies to reduce this rate and improve accuracy: retraining of radiologists in FNAC procedures, more vigorous sampling, on-site evaluation of specimens by cytopathologist or cytotechnologist, exclusive use of stereotaxic guidance, stereotaxic equipment calibration program, and verification of initial needle placement. RESULTS. Of 77 patients with impalpable abnormalities who underwent FNAC with the new protocol, six (8%) had insufficient specimens for cytologic diagnosis: Four were incorrectly judged to contain sufficient material at the time of FNAC, one refused to complete the FNAC, and one had a vasovagal reaction, Of the six cases with insufficient specimens, four were benign at biopsy, one was malignant, and one was determined to be benign on the basis of mammographic stability. CONCLUSION. Modification of techniques and implementation of a quality assurance program can significantly improve the insufficient specimen rate for FNAC. Correlation of mammographic and cytologic findings also improves the management of these cases.