This study examined how the mindsets and feedback preferences of 91 Thai undergraduate students in an English composition course influence their writing skills. Using a mixed-methods approach, the research gathered data on students' mindsets, feedback preferences, and writing outcomes. While most students displayed a fixed mindset and were reluctant to accept feedback, qualitative results revealed they were generally positive about feedback and believed it could enhance their writing. However, no direct connection was found between their overall mindsets, feedback preferences, and writing outcomes. Yet, qualitative data suggested a positive relationship between their attitudes towards written corrective feedback (WCF) and their writing improvements. These findings suggest that teaching strategies should focus on modifying EFL students' mindsets and attitudes towards feedback.