Background An organized, population-based, colorectal cancer screeningprogramme was initiated in England in 2006 offering biennial faecaloccult blood testing (FOBT) to adults aged 60-69 years. Organizedscreening programmes with no associated financial costs to the individualshould minimize barriers to access for lower socio-economic status(SES) groups. However, SES differences in uptake were observed inthe pilot centres of the UK programme, so the aim of this analysiswas to identify the extent of inequalities in uptake by SES, ethnicdiversity, gender and age in the first 28 months of the programme.DesignCross-sectional analysis of colorectal cancer screening uptake data.MethodsBetween October 2006 and January 2009, over 2.6 million adults aged60-69 years were mailed a first FOBT kit by the five regional screeninghubs. Uptake was defined as return of a test kit within 13 weeks.We used multivariate generalized linear regression to examine variationby area-based socioeconomic deprivation, area-based ethnicity, genderand age.Results Uptake was 54%, but showed a gradient across quintilesof deprivation, ranging from 35% in the most deprived quintile to61% in the least deprived. Multivariate analyses confirmed an independenteffect of deprivation, with stronger effects in women and older people.The most ethnically diverse areas also had lower uptake (38%) thanother areas (52-58%) independent of SES, age, gender and regionalscreening hub. Ethnic disparities were more pronounced in men butequivalent across age groups. More women than men returned a kit(56 vs 51%), but there was also an interaction with age, with uptakeincreasing with age in men (49% at 60-64 years; 53% at 65-69 years)but not women (57 vs 56%).Conclusions Overall uptake rates in thisorganized screening programme were encouraging, but nonetheless therewas low uptake in the most ethnically diverse areas and a strikinggradient by SES. Action to promote equality of uptake is needed toavoid widening inequalities in cancer mortality.