This paper focuses on Mirror Writing, the process of writing words and messages completely backwards. Leonardo da Vinci was famous for writing all of his notes and ideas using Mirror Writing. No one know for sure why he did it, although many believe it was to prevent others from stealing his ideas. This paper allows students to both decode a message written using Mirror Writing and allows them to write a message of their own. This activity goes great with any lesson on Leonardo da Vinci, or can simply be used as an enrichment activity.