Peer assessments are often used in English as a Foreign Language (EFL) or English as a Second Language (ESL) writing classes, and there are many studies that have measured students' perceptions of peer assessment activities. The current literature presents contrasting findings on these perceptions; therefore, this empirical study used structural equation modeling to investigate how students' implicit theories of writing intelligence shape their perceptions of peer assessments. The results indicated: 1) students who endorse the incremental theory of writing intelligence are more likely to have positive perceptions of peer assessments; 2) students' motivation to learn how to write in English is a significant mediator in the process; and 3) students who endorse the entity theory of writing intelligence may have negative perceptions of peer assessments. This study contributes to the literature in three ways. First, it provides evidence that students' implicit theories of writing intelligence (among other factors) impact their perceptions of peer assessments. Second, it affirms that students' implicit theories can predict their motivations in an EFL context. Third, it demonstrates that, although rarely used, the implicit theories of intelligence are a useful theoretical framework for EFL/ESL writing education and research.