The arthroscopy of temporomandibular joint (TMJ), in the early 1980s together with the development of magnetic resonance allowed us to understand diagnostic findings never seen before concerning this joint: synovitis, chondromalacia, perforation of the articular disc or free articular bodies. However we appreciated that patients undergoing TMJ arthroscopy improved because of the irrigation with solution and the movement of the arthroscope over the articular surfaces. This technique (lysis and lavage) does not seem to provide its good results by the changes of the disc position but due to the removal of the chemical mediators. It also increases the disc mobility and possible promotes denervation of the retrodiscal tissue. Subsequent to the development of lysis and lavage several arthroscopic techniques with the purpose of disc repositioning appeared. However, it was soon appreciated that reposition was only possible by different techniques if the disc is minimally deformed and it present mild anterior displacement. Obviously some authors have no observed different results between arthroscopic lysis and lavage and operative arthroscopy. But nevertheless both arthroscopic methods have shown a real improvement in terms of pain and mandibular function, and is clearly indicated for the initial treatment of most symptomatic TMJ intracapsular disorders that have not been resolved by properly performed routine non surgical treatment and where open surgery could be considered as aggressive and excessive treatment. Arthroscopy in the hands of a skilled practitioner can be a useful diagnostic and therapeutic adjunct but TMJ arthroscopy is a highly effective treatment for chronic closed lock pf the TMJ, but it is best used as part of a wider treatment regimen that includes physiotherapy, and occlusal splints to prevent recurrences.