Although multimodality has received vigorous attention and debate in English as a foreign language (EFL) research and classroom pedagogies, the practicality of using multimodal activities in curricula that are designed to teach language skills rather than multimodality is under researched. This paper contributes to the ongoing need for practical applications of multimodality in classroom contexts by describing how a multimodal video project was introduced into an EFL classroom in a Japanese university. The class was following a communicative curriculum prescribed by the university, which had not previously focused on multimodal approaches. The multimodal project was used to assess student's communicative performance. The students worked in groups to create public service announcement (PSA) videos, with the aim of delivering an informative message to highlight a health or social issue that they felt was important. In the project the students: (1) analysed several PSA videos; (2) researched social and health issues; and (3) worked together to plan, film, and edit a final digital product that was displayed in class for their peers. The authors found that the multimodal project worked successfully as a means of assessing communicative language because it generated a wide range of learning opportunities for improvement in English language proficiency and the students could engage in communicative activities with a high degree of autonomy and motivation. Moreover, students could gain experience communicating through multimodal platforms and improve their understanding of multimodal literacies. However, the multimodal project created challenges for the teacher in how to give effective feedback on students linguistic output as well as their multimodal output within the constraints of a busy language classroom.