The learning and developmental losses from preprimary program closures due to COVID-19 may be unprecedented. These disruptions early in life can be long-lasting. Although there is evidence about the effects of school closures on older children, there is scarce evidence on such losses for children in their early years. This article is among the first to quantify the actual impact of pandemic-related closures on early child development, in this case, for a sample of young children in Chile, where school and childcare closures lasted for about a year. We use a unique data set collected face-to-face in December 2020, which includes child development indicators for general development, language development, socioemotional development, and executive function. We find adverse impacts on children in 2020 compared to children interviewed in 2017 in most development areas. In particular, 9 months after the start of the pandemic, we find a loss in language development of 0.25 SD.