Gel-based and spectrophotometric assays were used to demonstrate expression of a manganese-dependent peroxidase (MnP) activity in culture filtrates of the ectomycorrhizal basidiomycete Tylospora fibrillosa. PCR amplification using a primer pair specific for a 260 bp fragment from the 5′-end of a gene encoding an H3-like MnP isozyme in Phanerochaete chrysosporium, produced single amplification products of 260 bp from DNA extracted from two isolates of T. fibrillosa. The amplified fragment from T. fibrillosa had a 93.7% nucleotide overlap (over 201 bases) with a published sequence for a 260 base amplification product from the P. chrysosporium H3 MnP isozyme gene, strongly suggesting the presence of a homologous gene in the ectomycorrhizal fungus. The results are discussed in the context of lignin degradation by ectomycorrhizal fungi.