During the past decade, substantial progress has been made in the development of new approaches and methods for the serological diagnosis of the mycoses. Clinically relevant antigens have been adapted for use in immunoassays for the detection of specific antibodies, and methods that detect fungal antigens in body fluids have been progressively refined. Nevertheless, few of the novel serological techniques have as yet found widespread clinical use. Reasons for this apparent discrepancy include the paucity of clinical data that substantiate improved predictive value for disease of antibody tests that use specific immunodominant antigens. The usefulness of detection of antigenemia in invasive candidiasis and invasive aspergillosis has been limited by the rapid clearance of Candida mannan and Aspergillus galactomannan from serum, which results in only moderate sensitivity for disease. False-negative results are especially frequent when single serum samples are tested in cases where fungal infection is clinically suspected. The detection of antigen in samples of urine collected serially may circumvent this problem in the future. The limited dissemination of methods for the detection of fungal antigens is also due to the slow development of simple and reliable commercial kits.