Within this survey, conducted by the Italian Group for Mammography Screening (GISMa), individual data are collected yearly on more than 50% of all screen-detected operated lesions in Italy. In 2004, overall results show a good diagnosis and treatment quality and an improving trend over time. Critical issues have been identified in waiting times, compliance to the recommendations on not performing frozen section examination on small lesions and on performing specimen X-ray. Pre-operative diagnosis has reached an acceptable level, but room for improvement still exists. The sentinel lymph node technique (SLN) was performed on the axilla in almost 70% of screen-detected invasive cancers, avoiding a large number of potentially harmful dissections. On the other hand, potential overuse of SLN deserves further investigation. The detailed results have been distributed to local and regional screening programmes in order to enable multidisciplinary discussion and the identification of appropriate solutions to any problems documented by the data. Specialist Breast Units with adequate case volumes would provide the best setting for effective audits leading to quality improvement.