This research was carried out to investigate whether audio-visual feedback affects students' writing components and overall writing performance in flipped or traditional instruction. To reach the aim, the researchers used two experimental groups of medical students at Shiraz University of Medical Sciences; experimental group 1: audio-visual feedback was provided plus flipped instruction; experimental group 2: audio-visual feedback was provided plus traditional writing instruction. The researchers used 50 students' writing scores and examined the effect of audio-visual feedback on students' writing component(s): (content, organization, vocabulary, language use, and sentence mechanics) and their overall writing performance in both classes. For the pre-test data at the beginning of the semester, students were asked to write a paragraph, and after 3 months, for the post-test, students' midterm exam data were collected and analyzed. The researchers applied nonparametric tests to answer the research questions including the Mann-Whitney and Wilcoxon Signed Rank Tests since the distribution of the scores was not found normal. According to the results, post-test mean scores of all-writing components and all-writing performance in the flipped and traditional-instructed groups were greater than those in the pre-test. It shows that audio-visual feedback improved the writing skills of the participants in both groups. Furthermore, all writing components and writing performance of students in the flipped-instructed group outnumbered their counterparts in the traditional group. It revealed that using audio-visual feedback in the flipped instruction has a more positive effect on improving students' writing components and writing performance compared with the traditional writing instruction.