Benzophenanthridine alkaloids represent one of the most diverse subclasses within the benzylisoquinoline alkaloid family. These alkaloids, which include several with medical and industrial applications, are biogenetically related to the protoberberine, protopine, and secoberbine alkaloids and share an important set of biosynthetic reactions. This chapter presents a review on the biosynthetic process, applications, and possible functions in planta. Future research trends, at the light of synthetic biology approaches, are also considered.