The continued increase in the number of students participating in online degree programs has led to an increase in the number of students taking online composition courses. Currently, most online writing programs replicate approaches used in face-to-face composition courses and simply transfer them to the online learning environment. However, there is a need to develop teaching practices and approaches to feedback designed specifically for online learning environments. This quasi-experimental study examined whether the use of a combination of audio-visual and text-based commentary in online writing courses was more effective in promoting substantive revision and improvement in students' writing than the use of text-based commentary alone. The multimodal feedback group showed higher rates of improvement in areas of audience and purpose between first and final drafts than students in the text-only group. Results also indicated that receiving a combination of audio-visual and text-based feedback had a marginally statistically significant effect on categories of content (p = 0.08) and final draft quality (p = 0.06); the effect for both categories was considered medium, partial ?[superscript 2] = 0.07. While most previous studies on audio or video feedback have focused on student perceptions of the feedback, this study, by focusing on efficacy, has helped generate empirical data regarding the pedagogical usefulness of audiovisual feedback in online learning environments.