Monoterpenes, in special limonene and its derivatives, are well studied in the literature due to their several properties. They are well recognized as major components of essential oils; some of them, are important industry residues, and others present some important biological activities. In this review, the biotransformation of the inexpensive limonene into flavor compounds was briefly reviewed and the main pathways for limonene biotransformation are presented. Furthermore, some important biological properties of these compounds were also considered, like bactericidal activity, induction of immune response, and role in disease prevention, with a little emphasis on some possibilities related to the mechanisms of anticancer action.