Four strains of a novel heterothallic yeast species were isolated from pollen storing cells of a honeycomb of honey bee (Apis mellifera) in Hungary. Analysis of the D1/D2 domain of the large subunit ribosomal RNA gene sequences placed the strains in the Trichomonascus clade. The four strains share identical D1/D2 sequence and differ by twenty-four substitutions and nine indels from the genetically most closely related species, Blastobotrys attinorum. The name Trichomonascus apis is proposed to accommodate the new species. The carbon source assimilation spectrum of Trichomonascus apis is rather broad. Unlike Blastobotrys 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- Y-48476IT), respectively.