Introduction: The Netherlands was one of the first countries in Europe to offer breast, colorectal and cervical cancer screening tests free of charge. Yet, a significant share of migrants in the Netherlands forgo the use of these preventive screenings. Qualitative research suggests, that lack of system knowledge on how the healthcare system operates (e.g. age eligibility of cancer screenings), is one factor contributing to this underuse among migrants. However, little is known about the extent to which migrants differ from natives in their system knowledge and about potential causes of this ethnic gap. The contribution of this study is therefore twofold: First, we examine whether migrants in the Netherlands have lower system knowledge regarding cancer screenings than the natives. Second, we examine which factors explain potential ethnic differences in system knowledge between migrants and non-migrants. Method: Using the Longitudinal Internet Study for Social Sciences (LISS), we matched newly collected data on system knowledge about healthcare with Health module (wave 14). To assess the difference in system knowledge among migrants and non-migrants, while taking into account potential selection bias, we applied propensity score matching, one-to-one matching procedure with no replacement. We compared first generation non - Western migrants (FNWM) and second-generation non-western migrants (SNWM) with their most similar non-migrants group regarding their knowledge about breast, colorectal, and cervical screening. A Blinder-Oaxaca decomposition with non-matched samples was used to examine which factors can explain the differences in system knowledge among migrants and non-migrants. Results: Our results show that first generation migrants have lower system knowledge about all three screening tests, while second generation migrants differ from non-migrants only with regard to knowledge about breast and colorectal cancer screenings. The ethnic differences found are not caused by personal or social factors such as ...