Preliminary results of a clinical study designed to compare clinical performance of digital breast tomosynthesis (DBT) versus standard full-field digital mammography (FFDM) in a diagnostic population are presented and discussed. Paired tomosynthesis and mammography examinations were analyzed by three experienced radiologists. One hundred single-breast cases were analyzed. Findings were rated in terms of lesion conspicuity, classified using the ACR BIRADS scale and compared with the truth. Statistically significant differences were found in lesion conspicuity for all radiologists, showing tomosynthesis superior to mammography. Finding classifications (BIRADS) were evaluated by ROC analysis. The results obtained from tomosynthesis images were consistently superior to FFDM for all readers. The difference was statistically significant for one radiologist. The results demonstrated DBT superiority for conspicuity of findings and showed potential for superior clinical performance.