Perinatal depression has been linked with deleterious child development outcomes, yet maternal depression interventions have not been shown to have lasting effects on child development, and evidence is not available from countries of low or middle income. In the Thinking Healthy Programme cluster-randomised controlled trial, a perinatal depression intervention was assessed in Pakistan in 2006-07. The intervention significantly reduced depression levels 12 months post partum compared with a control. We aimed to assess the effect of this same intervention on the cognitive, socioemotional, and physical development of children at around age 7 years.