There is an increasing interest in the rising campaign costs in state legislatures. Our knowledge of these trends, however is limited by the fact that campaign finance data were generally unavailable until a few years ago. Because of the lack of information, most previous research was limited to either one state or a single time period. In this research note, state legislative campaign expenditure data are analyzed for two time periods in four states. We find that the rise in expenditures is conditioned by two contextual factors: the degree of competition for party control of the chamber, and the level of state legislative professionalization. Strong evidence also exists that incumbents are increasing their expenditure advantage over challengers, and that fewer candidates are running for state legislative office.