Background: Home visiting programs are widely endorsed for preventing child maltreatment. Yet, knowledge is lacking on what and how individual program components are related to the effectiveness of these programs. Objective: The aim of this meta-analysis was to increase this knowledge by summarizing findings on effects of home visiting programs on child maltreatment and by examining potential moderators of this effect, including a range of program components and delivery techniques. Methods: A literature search yielded 77 studies (N=48,761) examining the effectiveness of home visiting programs, producing 174 effect sizes. In total, 35 different program components and delivery techniques were coded. Results: A small but significant overall effect was found (d=0.135, 95 % CI (0.084, 0.187), p<0.001). Programs that focused on improving parental expectations of the child or parenthood in general (d = 0.308 for programs with this component versus d = 0.112 for programs without this component), programs targeting parental responsiveness or sensitivity to a child's needs (d = 0.238 versus d = 0.064), and programs using video-based feedback (d = 0.397 versus d = 0.124) yielded relatively larger effects. Providing practical and instrumental assistance was negatively associated with program effectiveness (d=0.044 versus d = 0.168). Further, program effects were larger when percentages of non-Caucasians/non-Whites in samples and follow-up durations increased. Conclusions: In general, home visiting programs can prevent child maltreatment only to a small extent. However, implementing specific components and techniques can improve program effectiveness.