Since time immemorial mushrooms are being used for food and medicinal purposes by humans. According to Romans, mushrooms are considered as ‘Food for Gods.The importance of mushrooms lies in its consumption as food, in pharmacology as medicine and also it has gained lot of importance as an item of commerce all over the world.The demand of mushrooms as food supplement is increasing as the nutritional and therapeutic values of mushrooms are known. Several studies have been carried out on the chemical composition and nutritional qualities of different species of mushrooms. The wood decaying Lentinus species are edible as these contains significant amount of proteins, lipids, fats, minerals and vitamins. The mushroom, Lentinus polychrous Lév. is edible and commonly consumed in north eastern and northern regions of Thailand. The present study was to investigate the amino acid, fatty acid and mineral contents in Lentinus polychrous Lév.