Background and aims. The increasingly frequent use of mammography for the early diagnosis of breast cancer and the consequent identification of mammary lesions at a preclinical stage raises the fundamental problem of the differential diagnosis between non-suspected non-palpable lesions (NPL) which can therefore be monitored over time and suspected NPL or definite carcinoma requiring histological confirmation and surgical biopsy. The diagnostic accuracy of mammography alone is not sufficiently high to differentiate benign lesions from malignant or strongly suspected ones. The use of surgical biopsy in the event of suspected NPL could be significantly reduced by the use of stereotaxic cytology which would improve the diagnostic accuracy of mammography. Methods. The study refers to 72 suspected NPL undergoing surgical biopsy after having performed stereotaxic cytology on a sample taken with a dedicated mammographic device (Mammotest- TRC). Results. The rate of inadequate samples for correct cytological evaluation was 16.1%. Of the 72 NPL undergoing surgical biopsy, 40 (55.5%) were found to be carcinomas and 32 (44.5%) were benign lesions. The sensitivities of mammography alone and cytology alone in identifying infraclinical breast carcinoma were respectively 0.85 and 0.95. If the results of the two methods were evaluated together, the level of sensitivity was 0.98. Conclusions. The use of stereotaxic cytology enables a marked improvement to be achieved in the diagnostic accuracy of mammography for the identification of suspected NPL to undergo surgical biopsy, notably reducing the cost of biopsy (number of benign lesions for each carcinoma diagnosed) and consequent discomfort for patients