The important role of early self-regulation skills has been repeatedly demonstrated in research. However, there is a lack of studies that have simultaneously examined the influence of hot and cool self-regulation skills on school performance and behavior problems in a longitudinal design from preschool to elementary school and controlling intelligence. Our study was conducted in Germany with a total sample of N = 434 preschool-age children (age range from 5 to 7 years). In the German education system, children in the last year before starting school are considered preschool children. Relying on structural equation modeling, we found that children's intelligence and cool self-regulation skills are important for their school success. In addition, cool self-regulation skills in preschool are associated with behavior problems in elementary school. Since cool self-regulation predicts academic success even when controlling for intelligence, early intervention methods promoting cool self-regulation skills can positively affect subsequent school development. Likewise, a reduction of problem behavior patterns can be reached.