In addition to genomic mutations, broad epigenomic alterations contribute to the development of every type of cancer. The epigenome consists of modifications to DNA and chromatin that do not alter the underlying DNA sequence yet are heritable across cell divisions and regulate gene expression. Epigenetic mechanisms include DNA methylation, posttranslational histone tail modifications, and non-coding RNA. Tumors exhibit epigenetic signatures that vary drastically from healthy tissue, and these signatures include the silencing of tumor-suppressor genes. Myriad environmental factors including metals, synthetic chemicals, stress, and more can alter the epigenome. This may be a mechanism by which environmental exposures contribute to the development of cancer. In this educational session, epigenomics and its role in carcinogenesis will be briefly introduced. Then, evidence for the impact of environmental exposures on the epigenome will be presented as it relates to cancer risk.