Thirty-five years ago, the terms apicoectomy, semilunar flap, and failure characterized the scope of endodontic surgery. During the intervening years, basic research and clinical experience have catapaulted this area of dentistry to a level of refinement at which consistent long-term success is virtually assured. In summary, it is important to recall the principles of endodontic surgery that dictate treatment. The most important include the following: (1) The semilunar flap must be disregarded; (2) an "apicoectomy" is virtually never definitive treatment and referring to endodontic surgery as an "apicoectomy" should be discouraged; (3) careful considerations must be paid to all factors governing flap design. Finally, it must be realized that although periapical surgery has become a far more predictable treatment, it still is not a substitute for conventional endodontics, except in very rare situations.