The moisture level in biomass fuels potentially impacts efficiency in conversion to power. This paper examines the efficiency and net power output of a circulating fluidized bed gasifier-combined cycle with flue gas drying for a range of as-received raw bio mass moisture contents and levels of pre-gasification drying. Due to the lack of empirical data available, a modeling approach is used to simulate the effect of varying moisture content in the gasifier feed biomass. Below 30%, the raw-biomass moisture content has a negligible effect on the cycle efficiency and net power output. Higher moisture contents significantly reduce cycle efficiency. For a specified as-received biomass moisture content, drying prior to gasification increases overall efficiency, but the gains in efficiency decrease with increasing levels of drying.