This study evaluated the impact of a parenting intervention on children's cognitive and socioemotional development in a group of caregivers and their 21-to-28-month-old children in a low-income South African township. A randomized controlled trial compared an experimental group (n = 70) receiving training in dialogic book-sharing (8 weekly group sessions) with a wait-list control group (n = 70). They were assessed before the intervention, immediately following it, and at a six month follow-up. The intervention had positive effects on child language and attention, but not behavior problems, prosocial behavior, or theory of mind. Intervention caregivers were less verbally and psychologically harsh, showed more sensitivity and reciprocity and more complex cognitive talk. This program benefitted parenting and child development and holds promise for low-income contexts.