In Austria, since the early 1980s, the faecal-occult blood test is freely available within the annual health check-up system (> or =40 years of age/once a year). Since 2005 colonoscopy is recommended by the health authorities as a primary screening tool for asymptomatic persons older than 50 years (every 7-10 years). We report on the prevalence of self-reported participation and frequency of colonoscopy screening in Austrian men and women aged 40-79 years. The data analysed were extracted from a nationwide population-based cross-sectional study conducted in 2005. The study population consisted of 502 men and 553 women, which then was analysed by 10-year age groups. The questionnaire explicitly asked about a screening colonoscopy in asymptomatic persons and not for diagnostic examination in patients with symptoms. The survey revealed that of men 79.1% (n=397) knew about early detection of colorectal cancer in asymptomatic persons by screening colonoscopy and of women 82.1% (n=454). Of the 502 male respondents, 24.5% (n=123) were screened at least once and 9.8% were screened twice or more. Of the 553 female respondents, 23.7% (n=131) were screened at least once and 8.0% were screened twice or more often. The main location of colonoscopy screening was the hospital (men: 65.1%, women: 74.8%). Approximately a quarter of the respondents reported having had at least one screening colonoscopy. Compared with mammography screening (82%) and prostate cancer screening by digital rectal examination alone or combined with a prostate-specific antigen test (56%) the participation is low.