The Program for International Student Assessment (PISA) 2012 utilized data from 63 countries and economies to generate research questions that centered on the contribution of mathematics self-efficacy, opportunity to learn (OTL), and how their interplay affected students' mathematical performance. This study reveals that in a majority of the surveyed countries/economies, students' OTL can enhance the positive relationship between mathematics self-efficacy and mathematical performance. Path analysis further demonstrates that in 61 out of the 63 countries/economies, students' OTL positively affect their mathematics self-efficacy, which subsequently enhances mathematical performance. It was observed that students with more OTL typically exhibit higher math performance, but this effect is explained by the mediating influence of having more mathematics self-efficacy.