In this paper we evaluate the principal direct costs (staff, capital and maintenance equipment, supplies, hardware and software system, mail, advertising campaign) of the mammographic screening programme "Prevenzione Serena" (Torino), from the recruitment time to the diagnostic assessments of screen positive cases. On the basis of the annual situation of a screening Unit which supplies two-view mammographies, read by two radiologists, and of a 60% attendance rate and a 5% recall rate, we estimate a total annual cost of 1.4 thousand million lire (875,000$), a cost per invited woman of 38,600 lire (24$), per tested woman of 64,400 lire (40$) and per breast cancer detected of 9.2 million lire (5,750$). Staff accounts for about 60% of the total cost. We evaluate also some alternative scenarios, with different hypothesis about the useful life of the equipment, the discount rate, the attendance and the recall rate.