This study experimentally manipulated two incentives for participation (monetary: paid participation for sessions and setting: group vs. individual) in a child behavior problem prevention program to analyze their effects on recruitment and retention of families. A population of 690 eligible families from 15 preschools located in socially disadvantaged neighborhoods was invited to participate in a parent training (PT) program. The study recruited parents by using advertisements that had information describing only the indicated condition (i.e., PT in group-unpaid, or PT individual-unpaid, or PT in group-paid, or PT individual-paid). Results demonstrate significant impact of payment on recruitment and initial attendance. Training setting alone (individual or group) did not significantly influence these rates. Editors' Strategic Implications: A compelling case is made for the utility of monetary incentives to increase proportions of low-income families in prevention research and programs. Evaluators and program designers should note the impressive use of the experimental design and hierarchical linear modeling to test the effects on recruitment.