Background: Post arthrocentesis exercise program has a positive effect on symptoms, pain and the range of joint motion. Aim: to evaluate the effect of a specific exercise program post temporomandibular joint arthrocentesis on symptoms severity, pain, and mouth opening. Research design: A quasi-experimental research design (study/ control groups) was utilized. Subjects: A sample of 40 patients. Setting: The study was conducted in the Oral and Maxillofacial Surgery Unit and outpatient clinic at Assiut University Hospital. Tools: Four tools were utilized: Tool I: Patient's assessment sheet included demographic data; Tool II:  TMD questionnaire; Tool III: Wong-Baker pain rating visual analogue scale; and Tool IV: Range of maximal mouth opening measured in mm. Results: There was a statistically significant difference between the study and control groups regarding temporomandibular disorder mean score at 1 month (5.65±3.48&9.75±4.99) and 3 months (2.05±4.3&7.05±4.24) postoperatively with p.value (0.005**& 0.001**) respectively. A significant decrease in the mean pain score for both groups at 1 month and 3 months compared with the preoperative period and 1 week postoperatively with  p.value (0.004**& 0.0001***). Also, there was a high statistically significant difference between the study and control groups regarding the mean score of the range of maximal mouth opening measured in mm (37.7±3.66& 33±4.58) at 3 months postoperatively with p.value (0.001**). Conclusion: The exercise program post arthrocentesis is more effective in decreasing symptoms severity, and pain and improving mouth opening. Recommendations: Applying the specific exercise program for patients with TMJ arthrocentesis to decrease symptoms severity, and pain and increase mouth opening.