Active and finished compost contains a diverse community of microorganism with varying metabolic mechanisms which can utilize a variety of compounds, including xenobiotic contaminants, as substrates or as co-metabolites. Such a property is shown to be a useful tool in the bioremediation of contaminated sites. The purpose of this review is to consolidate the current understanding of the remediation of hazardous waste contaminated sites through composting and the use of compost materials. The review focuses on the remediation of common contaminants found at superfund sites in the United States. The review is divided into three classes of compounds which require different pathways to remediation: hydrocarbons, which are typically degraded aerobically, chlorinated compounds which are degraded largely by anaerobic processes, and heavy metals which do not degrade but can be converted to less harmful and less bioavailable forms.