The organic acids composition of six wild edible mushroom species (Amanita caesarea, Boletus edulis, Gyroporus castaneus, Lactarius deliciosus, Suillus collinitus, and Xerocomus chrysenteron) was determined by an HPLC-UV detector method. The results showed that all of the samples presented a profile composed of at least five organic acids: citric, ketoglutaric, malic, succinic, and fumaric acids. Several samples also contained oxalic, ascorbic, quinic, and shikimic acids. In a general way, the quantitation of the identified compounds indicated that malic acid, followed by the pair citric plus ketoglutaric acids, were the main compounds in the analyzed species, with the exception of A. caesarea, in which malic and ascorbic acids were the most abundant compounds. The relative amounts and the presence/absence of each identified compound may be useful for the differentiation of the species.