This study examined the effects of captioned videos and an advance-organizer strategy in incidental learning of collocations. Videos were enhanced by (1) inserting various types of captions (i.e., full captioning, keyword captioning, and no captioning); (2) administering or not administering an advance-organizer activity prior to video viewing; and (3) the combined effects of these two variables. This study adopted a 2 (+/− advance-organizer strategy) × 3 (types of captioning) between-subjects design, resulting in six possible conditions. A total of 361 Chinese primary school students learning English as a second language (L2) each watched a series of four videos in one of the six conditions. Data from the post-intervention test revealed that full captioning led to better performance in incidental learning of collocations than keyword captioning or no captioning. Administering the advance-organizer strategy resulted in better collocation learning gains compared to no administration. Learners who completed the advance-organizer strategy in the full-captioning condition achieved the best results on incidental learning of collocations. Incidental learning of collocations occurs at a rate similar to the learning of single words. This article highlights the importance of fully captioned videos and an advance-organizer strategy for incidental learning of collocations among primary school L2 learners.