Temporomandibular dysfunction (TMD) represents a set of musculoskeletal disorders associated with the stomatognathic system and with a series of symptoms. And as a compensatory mechanism, changes in body posture may appear. The objective of the present study was to compare the muscular activity, through the EMG of the Temporal and Masseter muscles in symptomatic patients in different positions, before and after the physical therapy. Fifteen patients were submitted to the evaluation of muscular activity, through Surface EMG, Temporal and Masseter muscles, lying down, sitting and standing. Physical therapy was then performed. As a result we obtained a significant difference between position and condition variables at the same time with condition and momentum. Therefore, we can conclude that there was a significant difference in the comparison of Muscle Temporal and Masseter muscle activity, before and after physical therapy.