This paper reviews the international (non-U.S.) evidence on the benefits of early childhood interventions. A total of 38 contrasts of 30 interventions in 23 countries were analyzed. It focuses on studies applying a quasi-experimental or random assignment. Studies were coded according to: the type of intervention (cash transfer, nutritional, educational or mixed); sample size; study design and duration; country; target group (infants, prekindergarten); subpopulations of interventions; and dosage of intervention. Cohen's "D" effect sizes were calculated for four outcomes: cognitive gains; behavioral change; health gains; and amount of schooling. We find children from different context and countries receive substantial cognitive, behavioral, health and schooling benefits from early childhood interventions. The benefits are sustained over time. Interventions that have an educational or stimulation component evidenced the largest cognitive effects. (Contains 3 figures and 2 tables.)