Background: The purpose of this study was to evaluate the effect of a single-dose intravenous dexketoprofen administration for preventive analgesia on postoperative pain and reducing swelling in double jaw surgery. Material and Methods: The authors designed a prospective, randomized, and double-blind cohort study. Patients who have Class III malocclusion were randomly divided in two groups. 50 mg intravenous dexketoprofen tro-metamol were administrated 30 minutes before incision in treatment group, while intravenous sterile saline was administrated 30 minutes before incision in placebo group. The primary predictor variable was treatment group. Primary outcomes were pain, swelling and 24-hour opioid intake. Patient-controlled analgesia with tramadol was given for management of postoperative pain. Other variables were demographic and operation related parameters. Visual analogue scale was used to evaluate postoperative pain. 3dMD Face System (3dMD, USA) was used to mea-sure postoperative swelling. Data were analysed using two independent samples t test and Mann Whitney U test. Results: The study sample was composed of 30 patients with a mean age of 20,63 years and 21 were female. Preemptive dexketoprofen administration decreased postoperative tramadol consumption by 25.9% compared to placebo group, and there was a statistically significant decrease in VAS scores (p<0,05). There was no statistically significant difference between the groups in terms of swelling (p>0,05). Conclusions: Preventive administration of intravenous dexketoprofen provides adequate analgesic effect in the postoperative 24-hour period and reduces opioid consumption in orthognathic surgery.