Fungal diseases have contributed to death and disability in humans, triggered global wildlife extinctions and population declines, devastated agricultural crops, and altered forest ecosystem dynamics. Despite the extensive influence of fungi on health and economic well-being, the threats posed by emerging fungal pathogens to life on Earth are often underappreciated and poorly understood. On December 14 and 15, 2010, the IOM's Forum on Microbial Threats hosted a public workshop to explore the scientific and policy dimensions associated with the causes and consequences of emerging fungal diseases.