Recently, studies have been conducted on the chemical composition of fruiting bodies of the culinary-medicinal Honey mushroom, Armillaria mellea (Vahl.) P. Kumm. (higher Basidiomycetes). It is considered in Europe and Asia as edible and medicinal, when appropriately prepared, and has demonstrated the presence of different groups of organic compounds, including carbohydrates, sterols, sphingolipids, fatty acids, sesquiterpenes, non-hallucinogenic indole compounds, peptides, enzymes, adenosine derivatives, and many other components. Most of these metabolite groups possess potential therapeutic and dietary values. The results of quantitative analyses of indole compounds and heavy metals signal potential health hazards for humans. Some of the studies reviewed herein describe in detail the mechanism of symbiosis between A. mellea and the orchid species Gastrodia elata. This orchid is native to Asia, Australia, and New Zealand, and is used in therapeutics in official Chinese medicine.