The aim of this meta-analysis was to investigate effects of family literacy programs on the emergent literacy skills of children from low socioeconomic status families (0-6) and to establish which program, sample, study, and measurement characteristics moderate program effects. Outcomes of 48 (quasi-)experimental studies covering 42 different programs revealed a medium average effect of Cohen's d = 0.50 on immediate posttests and a marginal average effect of Cohen's d = 0.16 on follow-up measures. Together, effects of different moderator variables indicate that children benefit from targeted programs that focus on a limited set of activities and skills and that are restricted to one (training) context. Additionally, we found larger effects in experimental studies and when researcher-developed tests were used. Our outcomes not only provide guidelines for program developers but also call for more longitudinal research that examines how positive short-term changes as a consequence of program participation can be sustained over time.