The polypore genus Antrodia (Polyporales, Basidiomycota) in the strict sense consists of a small number of species grouped around the type species A. serpens in phylogenetic analyses. This distinct clade (Antrodia sensu stricto in our view) contains species of the Antrodia heteromorpha complex, A. macra coll. and Antrodia mappa (formerly Postia mappa). Nuclear rDNA ITS and tef1 data show that the Antrodia heteromorpha species complex includes four species: A. heteromorpha sensu stricto (mostly on gymnosperms, large pores and spores), A. serpens (on angiosperms in Europe, resupinate, smaller pores but large spores), A. favescens (smaller pores and spores, pileate species in North America, formerly known as Trametes sepium), and A. tanakai (a close kin of A. favescens in Eurasia). Antrodia albida is a synonym of A. heteromorpha sensu stricto. We combine A. mappa, A. favescens and A. tanakai in Antrodia and designate neotypes for A. albida and A. heteromorpha, and an epitype for A. serpens. We also compare the morphologically similar but distantly related A. albidoides and A. mellita, and conclude that A. macrospora and A. subalbidoides are synonyms of A. albidoides.