Because of the large-scale production and widespread use of poly(ethylene glycol) (PEG) and polyvinyl alcohol) (PVA), these products eventually find their way into the natural environment. Their microbial metabolic pathways have been well studied. Our laboratory has cloned the relevant genes involved in the degradation of PEG and PVA from Sphingomonas sp. strains 103 and 113P3, respectively. A 13.3 kb DNA fragment containing the PEG dehydrogenase gene was cloned and sequenced. This report presents data about the operon related to PEG degradation and the regulation of this operon. Similar gene structures were found in other PEGutilizing sphingomonads. In addition, the PVA degradation operon, which includes genes for PVA dehydrogenase and oxidized PVA hydrolase, was also investigated. These genes were located in tandem with little intergenic space between them, suggesting that both genes are expressed constitutively and polycistronically.