The effects of the invasion of the epigeic earthworm Dendrobaena octaedra on the forest floor microfungal community were studied in a 90 yr old lodgepole pine forest over 2 yr. Fungi were isolated from the L and FH layers and the A h and B m horizons 1 and 2 yr after the introduction of earthworms to plots. High density and biomass of D. octaedra correlated positively with fungal dominance and negatively with fungal richness and diversity in the FH layer and the A h and B m horizons. High worm density and biomass differentiated the fungal communities in the FH layer from those in the L layer and B m horizons and increased the similarity between the fungal communities in the FH layer and the A h horizon. Earthworm activities appeared to favour the presence of faster growing fungal taxa.