BACKGROUND: Colorectal cancer (CRC) screening reduces mortality but variation exists in uptake with poorer uptake in ethnic minority groups. We aim to evaluate the relationship between ethnicity and CRC screening uptake in West London. METHODS: CRC screening results from the Central London, West London, Hammersmith and Fulham, Hounslow and Ealing Clinical commissioning group collaborative between 2012-2017 were retrospectively analysed. These five clinical commissioning groups (CCGs) are located in West London. Compliance with screening according to ethnic groups was evaluated compared to the White British control. RESULTS: 155,038 individuals were screened. White British individuals had the highest compliance (52.6%). A maximal difference of 8.2% compliance was seen between CCGs. The odds of being less likely to participate was significant (p<0.05) in all ethnic minorities except for Asian Chinese on univariate and multivariate analysis (adjusted OR:1.091 p=0.88). CONCLUSION: This is the largest retrospective study focusing on the role of ethnicity in the uptake of CRC screening in England. Poor uptake of screening in all ethnic minorities in West London with the exception of Asian Chinese individuals, in particular, is a novel finding. A mandate to routinely collect ethnicity data, the use of a single more diverse census and further intervention is needed to understand this disparity and improve health inequity. WHAT DOES THIS PAPER ADD TO THE LITERATURE?: We clarify the independent role of ethnic minority as a risk factor for poor colorectal screening uptake in West London. Only Chinese individuals are an exception. This is an important avenue to address to increase screening uptake and decrease cancer mortality overall but to also improve health inequity.