Community schools offer children an integrated set of educational and social services, but sound scientific evidence on their effectiveness is lacking. Therefore, this study reviews the literature on community schools. First, we characterize community schools and find that their key activities are cooperating with other institutions, involving parents, and offering extracurricular activities. Second, we describe an exemplary community school for which causal evidence shows improved academic achievement. Third, we explore whether the three main activities of community schools influence academic performance, dropout, and risky behavior. Academic performance does not appear to be influenced by extracurricular activities. On the other hand, extracurricular activities do appear to be related to reduced dropout and risky behavior. In addition, there is a positive association of cooperation and parental involvement with academic achievement, and a negative correlation of these two factors with dropout and risky behavior. However, more causal evidence is needed before it can be concluded that community schools are effective.