The purpose of this study is to analyse the structural relations between L2 learners' mindsets, L2 grit and the L2 motivational self-system (L2MSS). The main driving force behind the study is the observation that mindsets have emerged as a significant variable in language-teaching research over the past years. The study was conducted with 403 L2 learners. To see the structural relations between and among the variables in the study, a structural equation model was used. The revised model showed that a growth mindset affects both the perseverance of effort (POE) and the consistency of interest (COI), which are the components that make up grit. Moreover, POE and COI mediate the relationship between the growth mindset and L2MSS, with the highest mediating impact between growth mindset and ideal L2 self. The study discovered that a fixed mindset only predicted ought-to L2 self/others. Finally, several theoretical and pedagogical implications are proposed based on the findings of the study.