A number of recent studies have shown epigenetic alterations associated with suicidal behavior. These epigenetic mechanisms, which alter gene expression via alternative mechanisms to the coding DNA sequence, result from environmental effects acting on the genome. Studies in rodents indicate that variation in the early environment will trigger these epigenetic modifications and recent human data suggest the same may be true in humans.The expression of a number of genes, which are involved in normal brain functions and that have been shown to be under epigenetic control, seem to be dysregulated in suicide. The present review briefly describes the main epigenetic mechanisms involved in the regulation of gene expression and discusses recent findings of epigenetic alterations in suicidal behavior.