The purpose of this article was to describe the incidence of mamma cancer and ductal carcinoma in situ (DCIS) two years after a screening mammography in women offered a screening mammography instead of a clinical mammography. The mammography was abnormal for 6.3% of the women, 0.1% had DCIS and 1.0% was diagnosed with mamma cancer. 1.0% of women with a normal mammography were diagnosed with cancer within two years of the mammography. More widespread use of screening mammography may contribute to a rapid and effective investigation of mamma cancer in asymptomatic women.