Screening of the colon cancer seems to be important to improve the results of the surgical treatment. There are different screening programs, the most common use the fecal occult blood (FOB) tests or colonoscopy.The aim of the study was to evaluate the results of the colon cancer screening based on the FOB test and perform the algorhytm improving the effectiveness of the screening.Material and methods. 941 patients with the positive results of the FOB (immunochromatographic method) test were investigated. In all cases the rectosigmoidoscopy for the detection of the lower GI tract pathology was done. 312 patients were qualified to colonoscopy.Results. Adenomatous polyps and adenocarcinomas were detected in 116 patients. There was no correlation between clinical symptoms and the colorectal cancer. The colorectal cancer was recognized statistically more common at the patients with previous detected neoplasia, in the colon and other organs, with hereditary nonpolyposis colorectal cancer and with inflammatory bowel diseases.Conclusions. The colorectal cancer screening based on the FOB can be effective in the early recognition of the bowel malignancy. The previous questionnaire can eliminate from the FOB screening the patients without indications (previously done colonoscopy or barium enema) or with directly indications for colonoscopy.