During endodontic treatment of any tooth, aesthetics must be considered in the same manner as during any other dental treatment. The most common aesthetic challenge associated with endodontics is the discoloration of natural tooth structure. The discoloration may be a result of pulp pathosis, especially pulpal hemorrhage prior to or during treatment, or it may be due to various endodontic and restorative materials placed in the pulp chamber. There are several simple measures that can be utilized during and following endodontic treatment to eliminate or reduce aesthetic deficiency. The learning objective of this article is to discuss internal bleaching of discolored pulpless teeth that have been endodontically treated. The discussion includes the chemical composition of bleaching agents and principles by which they function during the bleaching procedures.