Leaf anatomy of 25 species in 15 genera of Caladeniinae (Diurideae, Orchidaceae), excludingCaladenia,was investigated to determine diagnostic characters to be used in forthcoming, broad‐based cladistic analyses of the subtribe and to assess interspecific and intergeneric relationshipS. Of the characters examined, those that show the most variation among the study taxa are presence and types of trichomes, cuticular sculpturing, anticlinal walls of epidermal cells, heterogeneity of chlorenchyma, distribution and length: width ratios of stomata. Anatomical evidence supports the generic concept ofLeptocerasLindley but contradicts that ofDrakonorchisHopper&A.P. Brown.Paracaleanais not sufficiently distinct fromCaleanato warrant generic status.Lyperanthus serratusandL.suaveolensare hyperstomatic, a rare condition in Orchidaceae. On the basis of these and other characters,Lyperanthus,as currently circumscribed, is polyphyletic. From leaf structure Caladeniinae as now conceived is polyphyletic and comprises seven groups: (1)Caladenia, Leptoceras, Elythranthera, Eriochilus, Glossodia, Aporostylis;(2)Adenochilus, Rimacola;(3)Arthrochilus, Chiloglottis, Spiculaea, Leporella;(4)Caleana(includingParacaleana);(5)Bumettia;(6)Lyperanthus suaveolensandL.serratus;(7)Lyperanthus nigrican