Numerous studies have been conducted to improve students' writing performance through flipped instruction. However, some researchers question its effectiveness due to a lack of systematic design. This study aimed to create a flipped writing environment and investigate the effects of EFL students' writing motivation, metacognitive awareness, and self-efficacy on their flipped writing performance. The results showed that flipped instruction was more effective than non-flipped instruction in improving students' writing. Students in the flipped classroom were more motivated to write, had better self-regulation, and improved their writing performance. Metacognitive awareness had the most significant and positive impact on self-efficacy; writing motivation significantly affected flipped writing outcomes. No significant impacts on metacognitive awareness or self-efficacy were observed on flipped writing performance. Based on the investigation results, pedagogical implications, limitations, and future research directions were discussed and presented.