As a follow-up to an earlier report on the antihyperlipidaemic activity guided fractionation study on the chloroform extract from the sclerotia of the edible mushroom Pleurotus tuber regium, this present study is reporting the isolation of a sesquiterpene enol carboxylic from the active chromatography fraction of the chloroform extract of this edible mushroom. The purity of the compound was confirmed from TLC and Melting point determination. The chemical structure was elucidated using spectroscopic techniques (Mass spectrometry, 1&2D Nuclear magnetic resonance and Infra red spectroscopy). The isolated compound coded as compound P, exhibited molecular mass of 256 with molecular formular of C14H24O4 and from the 1 &2D NMR and IR analyses, the compound P was identified as a sesquiterpene enol carboxylic acid with a sytemic name of 2,3-dihydroxy-10-propylcyclodec-2-ene-1-carboxylic acid.