Background. Temporomandibular dysfunction syndrome (TMD) is a common disease among dental patients. It occurs as a consequence of malfunction of the tempromandibular and/or surrounding facial muscles. LED red light therapy is not been well established, and it is important to find out the role of this technique in the treatment of temporomandibular disorders. Aim of the Study. To evaluate the efficacy of the LED red light in the treatment of the tempromandibular dysfunction syndrome. Material and Methods. Fifty students of the College of Dentistry/University of Baghdad with myofacial pain associated with Tempromandibular Disorder volunteered to participate in this study and be evaluated during both treatment and follow-up periods. They were 40 (80%) females and 10 (20%) males. Patients were divided into 2 groups: Group A treated by TenDlite® Medical Device model 204 with a LED’s of wavelength 660 nm (red light) and Group B given placebo (no treatment at all) by just putting the TenDlite device near the tender points without battery and turning ON the device. Results. The changes in the pain value and number of the tender muscles in both groups were highly significant, only placebo group less but with no significant differences. Conclusions. This study showed that red LED therapy could be useful in improving patient’s symptoms regarding pain, clicking, and number of tender muscles. In addition, this study showed the importance of the psychological part of treatment of those patients. This trial is registered with TCTR20190406002.