Reading buddies programs, which pair older and younger students to read books together on a regular basis, are common in many U.S. elementary schools. Yet, the research base on these programs is limited. Therefore, we conducted a quasiexperimental study of a reading buddies program targeting vocabulary and comprehension. The program we studied paired fourth-grade students with kindergarten students to read, talk, play, and write together. In all, 16 Grade 4 classrooms and 16 kindergarten classrooms participated in the treatment group and in the comparison group. The treatment included 10 one-hour sessions implemented over the course of roughly 10 weeks. Analyses revealed effects of treatment on proximal measures of vocabulary for both kindergarteners and fourth-grade students. However, there were no effects on distal measures for either group. Teachers' perceptions of the program are presented, and findings are discussed in light of the extant literature.