Four strains of a novel heterothallic yeast species were isolated from pollen-storing cells of a honeycomb of honeybee (Apis mellifera) in Hungary. Analysis of the D1/D2 domain of the large-subunit (26S) rRNA gene sequences placed the strains in the Trichomonascus clade. The four strains share identical D1/D2 sequences and differ by 24 substitutions and nine indels from the genetically most closely related species, Blastobotrys attinorum. The name Trichomonascus apis sp. nov. is proposed for the novel species. The carbon-source assimilation spectrum of T. apis sp. nov. is rather broad. Unlike B. attinorum, it assimilates sucrose, trehalose, d-glucuronate and succinate and does not grow at 37 °C, thus enabling the two taxa to be distinguished. The type and isotype strains of Trichomonascus apis are NCAIM Y.01848T (=CBS 10922T =NRRL Y-48475T) and NCAIM Y.01849IT (=CBS 10923IT =NRRL Y-48476IT), respectively.