Although numerous microfungi have been described from Eucalyptus in recent years, this plant genus remains a rich substrate colonized by numerous undescribed species. In the present study several species and genera of ascomycetes were collected from symptomatic leaves or from leaf litter of this host in Australia, South Africa and Europe. New genera include those encompassing Alysidiella parasitica and Phlogicylindrium eucalypti genera et spp. nov. (hyphomycetes), and Fusculina eucalypti gen. et sp. nov. (a coelomycete). New species include Colletogloeopsis blakelyi, C. considenianae, C. dimorpha, ElsinoÃ« eucalyptorum, Harknessia rhabdosphaera, Neofusicoccum corticosae and Staninwardia suttonii. A new combination is proposed for Microsphaeropsis eucalypti in Readeriella, while new cultures, hosts and distribution records are reported for Cytospora diatrypelloidea, Mycosphaerella swartii,
Plectosphaera eucalypti and Valsa fabianae.