Philosophical debate about charter schools often results in theory and anecdotes overshadowing empirical research. This systematic review of trends in the charter school research over the last decade helps determine where empirical evidence exists and where new research is necessary. Findings reveal that student and school outcomes are the most common topics studied; however, a dearth of national, longitudinal research limits generalizability. Furthermore, the scope of the research was rather limited: most research examined a single state, district, or school. The article concludes with a discussion of possible new directions for research on charter schools. (Contains 7 figures, 4 tables and 5 notes.)