Aim: This study was designed to evaluate the occlusal splint with arthrocentesis as combination therapy for treatment of TMJ internal derangement. Subjects and methods: Forty-two patients (ranging in age 23-54 years) suffering from signs of TMJ internal derangement attending at Oral and Maxillofacial Surgery Department at Sayed Galal hospitals (Al Azhar university).The patients complaints were limited mouth opening,TMJ pain, and joint noises during function. The patients will be divided randomly into three groups .Group I: Patients in this group will be treated by occlusal splint .Group II : Patients in this group will be treated by arthrocentesis (saline injection) .Group III: Patients in this group will be treated by combination of arthrocentesis and occlusal splint .Each group contained patients suffering from anterior disc displacement with and without reduction. Clinical evaluation was performed before the procedure and at 1,2 weeks,1,2,3,and 6 months postoperatively .Maximum mouth opening,pain with visual analogue scale,and joint sound also were recorded at each follow-up visit. Results: All groups of this study showed improvement in maximal mouth opening,TMJ pain,and clicking sounds with variable degrees according to treatment modality. Conclusion: Although in patients with TMJ ID benefitted from each technique to a variable extent, arthrocentesis of TMJ followed by splint seemed to be superior in achieving rapid and prolonged improvement in TMJ ID compared with other techniques.