Engaging second language (L2) students in multimodal academic writing that leverages multiple semiotic resources has the potential to foster their awareness of audience, purpose, and other rhetorical features. This case study explores L2 students' engagement in a multimodal digital storytelling (DST) project. The study reports on how DST was integrated into undergraduate writing curriculum and how students' engagement in multimodal composition fostered their rhetorical awareness and influenced their perceptions of academic writing. The findings suggest that the process of transmediation (a process of translating meaning from one sign system into another) facilitated students' revision, directing their attention to rhetorical features of writing. Creating digital stories enabled students to make sophisticated and deliberate rhetorical choices to bolster their arguments and transmit their messages effectively. Students exhibited positive attitudes toward the integration of multimedia. The results suggest that thoughtful integration of DST and multimodality have unique affordances for L2 students' writing development.