We examined the effect of Head Start on parenting outcomes for children living in nonparental care, or living with someone other than biological, adoptive, or step-parent. Data came from the Head Start Impact Study, a nationally representative and randomized controlled trial of Head Start-eligible children and families. Parenting outcomes included receipt of supportive services, receipt of home visiting, parental involvement at home and at school, and frequency of spanking. Regression analyses indicated positive effects of Head Start on receipt of supportive services and home visiting, and on decreases in spanking, as well as marginal effects on greater preschool-based parent involvement (e.g., attending conferences and workshops and classroom volunteering). No effect was detected of Head Start on home-based involvement (i.e., frequency parent-child book reading and enrichment activities). These findings add to an emerging line of research suggesting that early childhood programs, such as Head Start, may be an effective and practical way of supporting non-parental families with preschool-aged children. Findings also identify potential areas for improvement in supporting non-parental families and the need for more research to further understand the role of early care and education in the lives of nonparental families. (author abstract)