This paper presents results of a pilot study investigating the effects of multimodality upon second language comprehension, with a view to informing future instructional design. An experiment was designed to compare the understanding of an authentic BBC audiovisual recording, which was presented to four groups of French undergraduate students (N=40). Group 1 was exposed to sound alone, group 2 to image and sound, group 3 to image, sound and L1 subtitles and group 4 to image, sound and L2 subtitles. Students were asked to produce a detailed written summary in English, with the help of their own notes. The results indicate that comprehension improves when learners are exposed to a text in several modalities. In addition, they suggest that L2 subtitling is more beneficial than L1 because it causes less lexical interference.