Pain in the masticatory muscles and temporomandibular joint is the main symptom of temporomandibular disorders. The etiology of temporomandibular disorder pain is multifactorial. Several studies have reported that there are predisposing, initiating and aggravating factors contributing to this disorder. Although factors such as trauma, occlusal discrepancies, stress, parafunctions, hypermobility, age, gender, and heredity have been implicated in the maintenance of temporomandibular disorder pain, there are still controversies regarding the actual etiology. This review will summarize the past and current concepts related to the etiology of arthrogenic- and myogenic-originated temporomandibular pain.