Mammography for breast cancer screening has been available in Austria free of charge since 1974 and has been explicitly recommended for mass screening since 1980. The type of screening is opportunistic. Evaluation has to rely on population-based data (mortality, stage distribution, screening prevalence). In a representative cross-sectional study (women aged 40-79 years, n = 566, conducted in 1995) 58% reported at least one screening mammography; the lowest prevalence was found in the age group 70-74 years: 39.3%, the highest in the age group 50-54 years: 71.4%. 23.1% reported at least 2 mammograms within an interval of less than 2 years; lowest prevalence 70-74 years: 10.7%, highest 50-54 years: 35.7%. Age-standardized mortality rate has stabilized since 1985. Since 1980 age-specific rates have increased significantly in all age groups > 54 years, but a decreasing tendency in most groups has been noted since around 1990. The incidence rates of stage II or worse tumors have increased significantly since 1982, except in the age groups 40-44 and 55-59 years; however, during the past 3 to 6 years the absolute rates of incidence of advanced tumors has decreased in alle age groups. The reduction of advanced cancers at diagnosis, followed by a reduction of mortality rates is plausible related to screening prevalence. More uniform decreasing trends should be expected in the years to come. If not, discontinuation of the current opportunistic form of screening without monitoring and evaluation, financed by public money, has to be discussed.