In recent years, a series of articles have examined the performance of charter schools with mixed results. Some of this research has shown that charter school performance varies by charter type or the age of the school (Bifulco & Ladd, 2006; Buddin & Zimmer, 2005; Hanushek, Kain, & Rivkin, 2002; Sass, 2006). However, this research has not examined the school attributes that lead to high- or low-achieving charter schools. In this article, we examine how student achievement varies with school operational features using student-level achievement and survey data for charter and a matched-set of traditional public schools from California. We did not find operational characteristics that were consistently related with student achievement, but we did identify some features that are more important at different grade levels or in charter schools versus in traditional public schools. We also examined the relationship between greater autonomy within schools, which is a major tenet of the charter movement, and student achievement and found very little evidence that greater autonomy leads to improved student achievement.