This study was conducted on 18 patients with painful TMg with limited mouth opening and clicking (disk displacement with reduction) not responding to conservative treatment who attended the outpatient clinic of oral surgery department, faculty of oral medicine, Cairo university. Patients were divided randomly into two groups; A underwent arthrocentesis and group B underwent prolotherapy. All patient were subjected to pre-operative assessment including detailed clinical history and examination, measuring maximum mouth opening (MMO), lateral movement to right and left sides and degree of pain in numerical scale ( from 0 to 10), and post-operative assessment by measuring MMO, lateral movement to right and left sides and degree of pain in numerical scale (from 0 to 10). And still presence or absence of clicking post operatively.Comparison between arthrocentesis and prolotherapy showed that Arthrocentesis was more efficient in decreasing the pain in comparison with prolotherapy after 6, 12, 18 as well as 24 weeks. Also arthrocentesis was better than prolotherapy in increasing maximal mouth opening after 6, 12, 18 and 24 weeks. Postoperatively in comparison to prolotherapy. Also arthrocentesis improved the right and left lateral movement postoperatively in comparison to prolotherapy after 6, 12, 18 and 24 weeks, comparison in clicking between arthrocentesis and prolotherapy showed no statistically significant difference between them in the study pre and post operatively.So, arthrocentesis according to our study is more efficient thanprolotherapy in treatment of painful joint.