With the exception of Coccidioides spp., human pathogenic fungi are not found among lists of microbes with potential for biological warfare and bioterrorism against humans. However, many human pathogenic fungi are easily obtainable from the environment, are highly dispersible and can cause significant disease after inhalation with relatively low inocula. When the biological and pathogenic attributes of certain human pathogenic fungi are considered using a formula for calculating the relative weapon potential of a microbe it is as apparent that some organisms such as Coccidioides spp. are comparable to other microbes for which there is significant concern. Our analysis suggests that the current indifference to fungi as potential biological weapons against human populations is probably a perception engendered by their non-communicability, lack of history of use or development as biological weapons, and a relatively low incidence of symptomatic disease following natural infection. Awareness of the weapon potential of human pathogenic fungi is an important consideration for greater preparedness against the threat posed by biowarfare and bioterrorism.