Veneer is one of the most revolutionary techniques developed over the past 25 years. When dental professionals realized that porcelain can bond onto the composite and therefore onto the tooth surface, it changed everyone's view. An attractive appearance with veneer has shown to increase people's self-confidence, personal relationship, and even the success in his or her career. Hence with veneer, it is possible to create amazing esthetic results and yet retain considerable solid tooth structure. Successful result depends not only on the clinical and laboratory technique used for veneer fabrication, but also on an understanding of scientific background of the procedure involved since the placement of porcelain is an irreversible procedure it requires conservative tooth preparation. Therefore, the criteria for porcelain veneer must be carefully reviewed before the procedure is undertaken for its long term success. The purpose of this article is to present the most important parameters such as inclusion and exclusion criteria, shade selection, tooth preparation, veneer placement(cementation), patient maintenance for determining long-term success of porcelain veneers.