Objective: To review published literature on the equity of participation in colorectal cancer screening amongst different population subgroups, in addition to identifying factors identified as barriers and facilitators to equitable screening. Studies were included in the review if they included FOBT as at least one of the screening tests. Method: Relevant published articles were identified through systematic electronic searches of selected databases and the examination of the bibliographies of retrieved articles. Studies of the association with colorectal cancer screening test participation, barriers to equitable participation in screening, and studies examining interventional actions to facilitate screening test participation were included. Data extraction and analysis was undertaken using an approach to the synthesis of qualitative and quantitative studies called Realist Review. Results: Sixty-three articles were identified that met the inclusion criteria. SES status, ethnicity, age and gender have been found as predictors of colorectal cancer screening test participation. This review also found that the potential for equitable cancer screening test participation may be hindered by access barriers which vary amongst population sub-groups. Conclusion: This review provides evidence of horizontal inequity in colorectal cancer screening test participation, but limited understanding of the mechanism by which it is sustained, and few evidence-based solutions.