A partial (634 bp) cDNA clone, AF1229, obtained from expressed sequence tags (ESTs) of solid-cultured basidiomes of Antrodia cinnamomea is homologous to the lipase gene in Rhizomucor miehei. 5'-rapid amplification of cDNA ends (RACE) and 3'-RACE amplification showed that the full-length lipase gene, Ac-LIP, has a 912bp open reading frame (ORF), a 183bp 5' non-coding region, and a 144bp 3' non-coding region. Ac-LIP contains the lipase consensus sequence, VTVVGHSLGA, and encodes a 303-amino acid polypeptide that appears to be an extracellular protein with a calculated molecular mass of 31.8 kDa. RT-PCR analysis suggested that Ac-LIP was strongly expressed during the basidiomatal formation stage of A. cinnamomea. When over-expressed in Escherichia coli, Ac-LIP yielded a protein that was capable of performing hydrolysis of trilinolein by gas chromatography/mass spectrometry (GC/MS) analysis. A. cinnamomea lipase represents the first enzyme of the lipase family from a basidiomycetous fungus, which has been characterized at the molecular level.