A novel method for the detection ofFusarium graminearum employing mid-infrared spectroscopy is described. In this study the fungus itself was determined on maize by pressing the ground sample against a diamond ATR-crystal, mounted horizontally in the sample chamber of an FT-IR spectrometer and recording the mid-infrared absorption spectrum. Multivariate data analysis was employed for the interpretation of spectra: Principal component analysis (PCA) was used to separate contaminated maize from uninfected samples. For concentrations higher than 8.23 mg/kg >80% of the samples were correctly classified with PCA. Spectra were correlated with HPLC results from reference measurements for ergosterol using principal component regression (PCR). A correlation coefficient of 0.9786 with an F-statistic of 107 was calculated (concentration range: 0.79-947 mg/kg ergosterol).