This note provides an overview of how psychological principles may be used as part of a seller's pricing strategy. The note defines the concept of psychological pricing and explains the motivations for firms to engage in it. Prominent practices and tactics, with detailed reference to the psychological and behavioral principles at play, are featured. Numerous examples are given to illustrate the material covered. The note also highlights several concerns companies might have in employing psychological pricing techniques, along with thoughts on how to mitigate or counter these reservations.