This study examined the clinical and synovial fluid analysis before and after arthrocentesis in patients with internal derangement. Eighteen patients with internal derangement were studied. Patients were divided randomly into two equal groups. Group (A) in which only arthrocentesis was performed and Group (B) which received arthrocentesis plus intra-articular injection of tramadol. Synovial fluid analysis was evaluated before the procedure and one month postoperatively in both groups. Intensity of joint pain was assessed using a visual analogue scale. Maximum mouth opening was recorded at each follow-up. TMJ sounds and palpation scores were noted as positive or negative. Tomograms were performed before treatment in both groups. Both treatments successfully increased maximum mouth opening and reduced TMJ pain; there were no complications. Difference between the groups was not statistically significant and a larger controlled study is necessary to clarify this use of tramadol.