The degradation of polydimethylsiloxane (Silicones) on a spiked standard soil matrix has been studied. Spiked soil was extracted to recover silicones, and the extract was examined by several analytical techniques, including gel permeation chromatography and high pressure liquid chromatography with an inductively coupled plasma emission spectrometer as the detector. Silicones were found to degrade rapidly to low molecular weight a,w-siloxanediol oligomers. Within 4-6 weeks, more than half of the initial spiked silicones is converted to a water soluble fraction consisting mostly of 1,1- dimethylsilanediol. Implications of this finding relative to the ultimate environmental fate of silicones is discussed.