The demand for After-School Programs (ASP) has increased in the last decades, mainly related to the reduced availability of the family to take care of children in the after-school period. This study aimed to compare two groups of children who attend (ASP group) or not ASP (comparison group), from the first and second grade, regarding their social skills and behavior problems. Teachers assessed 120 children (half by group) across three times (one before and two during the COVID-19 pandemic). A pattern of ASP attendance was determined, in order to understand whether ASP attendance influences social skills and behavior problems. The results indicated that children who attended ASP showed higher levels of self-control and assertion skills. Higher levels of hyperactivity were reported by teachers for both groups when children came back to school after the first COVID-19 lockdown. Parents enrolled their children in ASP mostly for safety; and ASP attendance had a positive effect on social skills and negative on behavior problems. The implications of attending ASP associated to a more positive child development are discussed.