MyTeachingPartner (MTP) is a web-mediated approach that provides ongoing support for teachers to improve the quality of their interactions with children. This study examined the effects of MTP on the preschool language and literacy development of children who are at risk for later academic difficulties. Results of this randomized controlled trial indicated that for English-only classrooms, teachers receiving a high level of support had students who made greater gains in language and literacy skills than teachers who only received access to a curricular supplement. Three implications are drawn from these findings: (1) on-going, video-based consultation holds promise not only for altering teacher-child interactions, but also improving children's learning, (2) technology allows teachers to receive intensive, effective support from a distance, and (3) there is still much to be learned about how professional development can support effective teaching of language and literacy skills to children whose home language is not English.