The aim of this study was to measure the direct costs of mammogram campaigns conducted by the Regional Health Division of Marília, São Paulo State, Brazil, in 2005 and 2006. A total of 11,952 mammograms were performed. Mammographic outcomes were classified according to BI-RADS. Cost analysis was based on the amount paid by the Brazilian Unified National Health System (SUS). Ten cases of breast cancer were diagnosed (0.84 per 1,000 mammograms), 70% of which between 50 and 69 years of age. The campaigns and follow-up cost a total of R$450,019 (U$280,000), with R$431,467 paid for 11,952 mammograms and R$18,552 for diagnosing 29 suspected cases and treating 3 cases of benign tumors and 6 cancer cases. Mean cost per diagnosed case was R$43,268. The high cost per diagnosed case highlights the need to implement effective screening programs and improve the quality of mammography services in this region of São Paulo State.