The introduction of temporomandibular joint (TMJ) arthroscopy by Onishi in 1970 (results published in 1975 and 1980) opened a new modality for TMJ treatment. The efficiency of arthroscopic lavage and lysis led in the 1990s to its simplification: TMJ arthrocentesis. Always associated with load control, physiotherapy, and elimination of any occlusal hazards, arthrocentesis, a simple procedure, entails less expensive and more available tools and is performed under local anesthesia. Although lacking direct visual inspection of the joint structures, it has become quite popular. Arthrocentesis is most efficient in localized joint pain and limited joint movements such as closed lock, anchored disc phenomenon, osteoarthritis, and various inflammatory diseases. In clicking joint, the results are somewhat controversial. The efficiency of arthrocentesis elicited many enquiries that led to the study and a better understanding of joint function and dysfunction and the actual role of disc location. The release of closed lock without disc repositioning was quite surprising; it improved our understanding of the pathogenesis of closed lock and led to the discovery of the anchored disc phenomenon. This was followed by the awareness of the joint-lubrication system and, in turn, alternative suggestions for the pathogenesis of TMJ disc displacement with and without reduction, open lock, and osteoarthritis, and ultimately by the development of an effective bio-lubricant. Awareness of the role of joint overloading led to the development of an interocclusal appliance that reduces intraarticular pressure; it has become a “must” support for arthrocentesis and any surgical intervention. In our view, arthrocentesis is the definitive indication of the need for surgical intervention and, therefore, should be the first in the cascade of interventions in TMJ disorders.