Identification, quantification, and location of fatty acids in the newly cultivated fresh mushroom, Lepista nuda, as well as three aromatic effluents (1-octen-3-ol, 1-octen-3-one, and 3-octanone) from mushroom homogenate, were established. The highest amounts of fatty acids as well as the three aromatic compounds formed and released were encountered in the gills rather than in the pileus or the stipe. Among these components, 1-octen-3-ol (“mushroom alcohol”) was the major aromatic compound trapped, and linoleic acid was the major fatty acid extracted, whatever the morphological tissue considered. Observed results indicate that the gills are the major compartment for the metabolic interconversion of fatty acids into aromatic compounds.