During the past two decades, Clinical and Laboratory Standards Institute (CLSI) antifungal susceptibility testing methods for both yeasts and molds have been developed and established in response to increasing invasive fungal infections and the release of multiple new antifungal agents. In addition, other methods including Etest, the disk diffusion test, and some CLSI modification methods have been intensively studied. Antifungal susceptibility tests are now routinely used for local epidemiological surveys to determine the susceptibility patterns of clinical isolates of fungi, the degree of antifungal activity of newly developed antifungal agents, and to predict the clinical outcomes of antifungal therapy for patients with Candida infections. It is anticipated that in the near future, antifungal susceptibility tests that can detect amphotericin B resistance, that can be used to establish the minimum inhibitory concentration (MIC) breakpoints of molds, and that can provide increased clinical guidance for antifungal therapy, will be developed. This review focuses on the various methods used for antifungal susceptibility testing and the clinical utility of antifungal susceptibility testing. (Korean J Clin Microbiol 2009;12:154-158)