This study examined parents' and toddlers' talk and viewing behaviour while co-viewing an educational infant DVD focused on teaching language. Sixty-four 12- to 25-month-old infants viewed a DVD in a laboratory with their parents. A cluster analysis on parent talk revealed three groups: High, Moderate, and Low Teaching Focus parents. The High Teaching Focus parents presented the greatest variety of words highlighted in the DVD, were most likely to label or describe what was on screen, and had the least amount of non-DVD related talk. Children of High Teaching Focus parents had the highest degree of engagement with the DVD. These children also said the greatest number and variety of target words and were most likely to say new words during the co-viewing session. Furthermore, parent talk significantly mediated the relationship between children's engagement with the DVD and their use of new words while co-viewing. The findings are discussed in terms of implications for how parents use educational infant DVDs to teach their children. Copyright © 2010 John Wiley & Sons, Ltd.