Comparatively high diversity of fungi (26 species) decomposing leaf litter were found in small lentic habitats (swampy pools) in mixed Gubiškiai Forest of Aukštadvaris Regional Park. Together with widespread aquatic and terrestrial fungi, 14 species of aero-aquatic hyphomycetes were found colonizing freshly fallen leaves of Quercus robur, Tilia cordata and Alnus glutinosa in autumn 2011. Of these, six species, Ardhachandra cristaspora, Candelabrum spinulosum, C. clathrosphaeroides, Dactylaria fusiformis, Helicodendron tubulosum and Xylomyces giganteus were recorded for the first time in Lithuania. In addition, a noteworthy new aero-aquatic fungus, preliminary placed in the genus Pseudospiropes by morphological characterization, was found on decaying leaves of Quercus robur. New records to the country and rare species are illustrated, their morphological and ecological peculiarities are discussed herein.