The moisture content of dead fuels is an important determinant of many aspects of bushfire behaviour. Understanding the relationships of fuel moisture with weather, fuels and topography is useful for fire managers and models of fuel moisture are an integral component of fire behaviour models. This paper reviews research into dead fuel moisture for the period 1991-2012. The first half of the paper deals with experimental investigation of fuel moisture including an overview of the physical processes that affect fuel moisture, laboratory measurements used to quantify these processes, and field measurements of the dependence of fuel moisture on weather, vegetation structure and topography. The second set of topics examine models of fuel moisture including empirical models derived from field measurements, process-based models of vapour exchange and fuel energy and water balance, and experimental testing of both types of models. Remaining knowledge gaps and future research problems are also discussed. Opportunities for exciting research in the future exist for basic fuel moisture processes, developing new methods for applying models to fire behaviour prediction, and linking fuel moisture and weather forecast models.