Antifungal susceptibility testing has been in routine use now for more than 15 years and has become a useful tool for clinicians who are faced with difficult treatment decision. Although most clinicians order susceptibility testing, much confusion still exists regarding the use of the results. Sufficient data have been generated to determine susceptibility trends for specific fungi against specific agents, but correlation data are minimal. Despite the lack of correlation data, antifungal susceptibility testing continues to provide useful information to assist with patient care.