['Participation rates in colorectal cancer (CRC) screening are rather low. We evaluated the interest of first degree relatives (FDR) of CRC patients to participate in a colonoscopy screening and compared the findings to controls with a negative family history.', 'There were 235 CRC patients diagnosed in our centre in 1984-2001. These were mailed an invitation letter for a preventive examination for their FDR older than 40 years and a questionnaire about occurrence of malignancies in their family. Colonoscopy was performed in 52 FDR and sex/age matched controls.', 'The questionnaire was delivered to 196 patients. Thirty four (17.3%) patients responded. Positive family history for CRC was reported in 12/34 (35.3%) patients, compared to expected 3.4 patients (p = 0.04; OR 4.2; 95% CI = 1.05-17.89). Fifty two of 94 (55.3%) FDR participated in a screening and CRC was diagnosed in 2 and CRA in 18 patients compared to 1 CRC and 9 CRA in control group (p = 0.04; Kaplan-Meier p = 0.04).'] Does positive family history promote participation in colorectal cancer screening?