Boletopsis smithii has a dull orange stem surface.
Bondarzewia berkeleyi is limited to eastern North America, is a hardwood associate, and has slightly larger (7-9 × 6-8µm) spores.
Bondarzewia mesenterica is limited to Europe, and other Bondarzewia spp. have ranges which are different from B. occidentalis.
Grifola frondosa forms more numerous, smaller and drab grey-brown fronds, 2-6 cm across, while Bondarzewia forms fewer large fronds, 7-12 cm across, in more colorful shades of brown with tinges of purple and orange. G. frondosa has a thinner (1-2mm), shallower pore layer, and smaller, more tightly organized, pores. G. frondosaspores are inamyloid, oval, smooth.
Meripilus giganteus blackens when bruised along cap edge and on pore surface.
Phaeolus schweinitzii has brown flesh, green to brown pores; B. occidentalis has white, pallid or at most beige flesh, cream pore surface.