If (a revision of) a conventional endodontic treatment is not possible or not successful, apical endodontic surgery can be indicated. The contemporary indications, the better retrograde preparation techniques with ultrasonic retro-tips, and the better visualisation of the operation area with an operation microscope can lead to higher success percentages. Moreover, the current developments in the field of compatible filling materials are promising. Also the application of lasers is promising, but has still to prove its clinical usefulness.