PURPOSE: To determine the costs and screening-related services in women undergoing screening mammography. MATERIALS AND METHODS: Study procedures were approved by the institutional committee for the protection of human subjects, and participants gave prior written consent. Data from a statewide mammography registry were used to identify imaging examinations, clinical consultations, interventional procedures, and pathology reports associated with screening mammography. The analysis included 99 064 women in the New Hampshire Mammography Network who underwent screening mammography between November 1, 1996, and March 31, 2000. Use of screening-related services in each case was tracked over an 18-month period, and procedure-specific national Medicare reimbursement rates from 2002 were applied for estimation of costs. Descriptive statistics (means, medians, standard deviations, 95% confidence intervals, frequencies, and percentages of resources and of costs) were calculated. RESULTS: The majority of subjects (85 809, or 87%) underwent screening mammography only. Of the 13 255 (13%) who underwent diagnostic imaging, additional mammographic views were obtained in most at the time of screening, within days or weeks of screening, or at short-interval follow-up. The total cost was $12 287 739. Approximately 80% ($9 777 670) of the total cost was related to imaging, and 68% ($8 410 313), specifically to screening mammography. Twenty percent ($2 510 069) of the total cost was associated with consultation and interventional procedures in only 2942 (3%) of the women, primarily those who underwent biopsy. Procedures resulted in benign findings in 2247 (76%) of the 2942. Mean total direct medical costs per capita were low ($99) in women who underwent screening mammography only, moderate ($286) in women who also underwent diagnostic imaging, and substantially greater in women who underwent biopsy ($993). CONCLUSION: While the largest component cost of screening mammography is that incurred in obtaining screening views alone, the highest costs per capita are associated with interventional procedures.