The ancient randomized-controlled trials of breast cancer screening have offered clear evidence that invitation to participate in mammography screening with/without clinical examination is effective in breast cancer mortality reduction und underline the detection sensitivity of mammography. Recently published criticism of both the effect and fundamental data handling could be shown to be untenable. Randomized studies underestimate the effect while well-designed observational studies do not systematically overestimate the magnitude of the effect. To transform high-quality study results in all-day's practice is a hugh challenge, but affordable as has been demonstrated in Great-britain, the Netherlands and Sweden.