Recent research suggests that caregiver-child extratextual talk during shared book reading facilitates the development of preschool children's oral language skills. This study investigated the effects of the amount of picturebook text on mother-child extratextual talk during shared book reading. Twenty-four mother-child dyads (children aged 3;01-3;11) were video-recorded as they read two books: low text and high text. Book reading interaction was transcribed, and mothers' extratextual talk coded for level of abstraction, mean length of utterance and lexical diversity. The mean number of extratextual utterances was calculated for mothers and children, separately. Low-text books facilitated a similar amount of extratextual talk, but higher rates per minute because of their shorter reading durations. The amount of text did not affect the level of abstraction, mean length of utterance, or lexical diversity of maternal extratextual talk. The amount of picturebook text should be considered by those developing and implementing interactive reading interventions. Low-text books facilitate the same amount and quality of extratextual talk in shorter time periods.