This study examines the effect of textual enhancement on learners' attention to and learning of multiword units from captioned audiovisual input. We adopted a within-participants design in which 28 learners of English as a foreign language (EFL) watched a captioned video containing enhanced (underlined) and unenhanced multiword units. Using eye-tracking, we measured learners' online processing of the multiword units as they appeared in the captions. Form recall pre- and posttests measured learners' acquisition of the target items. The results of mixed effects models indicate that enhanced items received greater visual attention, with longer reading times, less single word skipping and more rereading. Further, a positive relationship was found between amount of visual attention and learning odds: items fixated longer, particularly during the first pass, were more likely to be recalled in an immediate posttest. Our findings provide empirical support for the positive effect of visual attention on form recall of multiword units encountered in captioned television. The results also suggest that item difficulty and amount of attention were more important than textual enhancement in predicting learning gains.