We present the main results of the first national survey of organised screening programmes, conducted by the Italian Group for Colorectal Cancer Screening (GISCoR). During 2004, 18 programs, adopting faecal occult blood testing (FOBT), sigmoidoscopy (FS), or a combination of both, were active in Italy. Overall, 331,333 subjects were invited to undergo FOBT and 165,480 were screened; the attendance rate (51.3%) equals the best performances reported in the literature. Positivity rate was 5.4% at first and 3.9% at repeat screening: it increased with age and was higher among men than among women in all age groups. The average attendance rate at colonoscopy (TC) was 83% (range: 70%-100%; median: 85%). Completion rate of TC was 92%, with higher rates among males. At first screening, the detection rate (DR) per 1000 screened subjects was 2.8 and 11.6 for cancer (CRC) and "high-risk" adenomas (HRA) (> or =3 adenomas, 1 adenoma > or =1 cm, or with villous component >20%, or with high grade dysplasia) respectively; the corresponding figures at repeat screening were 1.2 for CRC and 4.9 for HRA. The DR of CRC and adenomas increased with age and it was higher among men than among women; 51% of screen-detected CRCs were at TNM stage 1. The positive predictive value (PPV) was 6.3% for CRC and 25.8% for HRA at first screening, and 3.6% for CRC and 15.1% for HRA at repeat screening. Given this high PPV of positive FOBT, to obtain a high attendance at TC is crucial. In the three FS programmes 15,688 subjects were invited and 4884 were screened (attendance rate: 31.9%). TC referral rates ranged between 7.6% and 14.0%, due to different referral criteria. Among subjects referred to colonoscopy the prevalence of HRA and CRC ranged from 7.9 to 9.9%. The overall DR (subjects with at least one advanced lesion) ranged from 5.5 to 7.0%. Comparing the DR at FS and FOBT in the same age range. FS showed a higher sensitivity both for HRA (DR was four times higher) and for CRC. In conclusion, colorectal cancer screening looks feasible. The reported experiences showed good results in terms of attendance and DR, although some critical aspects need to be carefully addressed when planning and implementing screening activity.