The aim of the present study was to evaluate the arthrocentesis using platelet-rich plasma (PRP) versus hyaluronic acid (HA) in treatment of temporomandibular internal derangement. Methods: Patient of present study were carried out on adult patients with TMJ internal derangement. Seventeen cases 10 females (61%) and 7 males (39%). The patient obtained from Oral Maxillofacial Department at Faculty of Dental Medicine Al-Azhar University. All patients have arthrocentesis before injection with PRP or HA or Saline: Group (A): receives PRP injection, Group (B) receives HA injection, and Group (C) control group receives saline only. Results: The results of this study were to evaluate the effect of PRP and HA Injections after arthrocentesis in the patients with TMID in patients who didn't respond to conservative treatment. PRP administration showed a significantly high effect than (HA) on pain free mouth opening, clicking and masticatory efficiency. Conclusion: PRP and HA were safe material to be injected in TMJ cavity without any complications regarding to its administration.