Introduction: The management of postoperative pain is an imperative for every surgical specialty, including oral surgery. Numerous studies continue to confirm that pain, including dental pain, is not adequately treated. Third molar surgery is one of the most common procedures in oral surgery. In fact, mandibular third molar surgery serves as a common model for evaluating the efficacy of postoperative pain management. This surgical procedure is carried out under local aesthesia by a trunk block of the inferior alveolar nerve. Quality of pain management depends on the choice of analgesic or their combination (multimodal concept), analgesic administration route (central or peripheral) and time of administration (preoperative, intraoperative or postoperative). Tramadol is a weak opioid analgesic with central acting properties. It was first synthesised in 1962. It is also an atypical opioid that has local anesthetic and analgesic effects different from other opioids. It has been reported that tramadol added to local anesthetics could improve its efficacy and reduce postoperative pain. Aims of the research: The aim of this research is to evaluate the effect of 50 mg tramadol added to 2% lidocaine with adrenaline on anesthetic quality and duration in inferior alveolar nerve block. Furthermore, the effect on postoperative pain, in respect of time till the first analgesic rescue medication and total amount of analgesic consumption, will be assessed. Hypothesis of this research is that tramadol added to lidocaine for inferior alveolar nerve block extends the duration of anesthesia, improves the quality of anesthesia as well as postoperative pain, prolongs the time till the first analgesic rescue medication and reduces the total analgesic consumption. Patients and methods: A prospective, randomized, double-blinded, split-mouth, placebocontrolled study was designed. Sample size mounted to 30 subjects, free of systemic disease (ASA I American Society of Anesthesiologists), 19 to 39 years old, with bilateral semi or fully impacted mandibular third molars that require surgical removal. Surgery was carried out in local anesthesia. For every patient, the third molar was randomly assigned to the combination of tramadol plus lidocaine or to saline solution (placebo) plus lidocaine for block before surgery. Minimum two weeks later second surgery was performed using the substance not used in the first surgical procedure. Quality of anesthesia was subjectively assessed by every patient, with the use of visual analog scale (VAS), in accordance to their perception of the level of discomfort during the operation. Block anesthesia onset time and duration of the anesthetic effect was recorded in minutes. Evaluation of the postoperative pain intensity was done using the VAS 2, 4, 6, 12, 24 and 72 hours after surgery. Furthermore, time till the first analgesic rescue medication and total analgesic consumption were also recorded. The statistical analysis was done using the χ2 test for categorical variables and Fisher-Freeman-Halton exact test, used when there were less than 7 variables per cell. For quantitative values, independent non-parametric t-test was used in case of normal distribution. Non-parametric tests that were used were Mann Whitney U test, Spearman’s rank correlation coefficient and Friedman dependent test. Result: A significant difference was observed between groups in the duration of the anesthetic nerve block. In the tramadol group, the duration of the inferior alveolar nerve block was shorter and amounted to 189,00 minutes (IQR (Interquartile Range): 156,5- 230,0), while in the placebo group, the anesthetic duration mounted to 214,50 minutes (IQR: 183,75-248,25) P=0,031. There was no significant difference between the groups in the anesthetic latency time (time for the anesthetic block onset; median for both groups was 4 minutes) P=0,362 and in the quality of anesthetic block, measured by VAS (visual analog scale). VAS was used to describe personal experience of the operation (median for VAS value for tramadol group was 2 and for placebo group was 3) P=0,552. There was no significant difference between groups in VAS values for postoperative pain intensity recorded 2, 4, 6, 12, 24, 48 and 72 hours after surgery (P=0,843 for 2 hours, P=0,703 for 4 hours, P=0,415 for 6 hours, P=0,614 for 12 hours, P=0,229 for 24 hours, P=0,371 for 48 hours and P=0.237 for 72 hours). There was no significant difference between groups neither in time till the rescue analgesic (median for tramadol group was 209,5 and median for placebo group was 217,0; P=0,495) nor in total analgesic consumption (on the day of operation P=0,214, first day after operation P=0,209, second day P=0,447 and third day after operation P=0,084). Conclusion: Tramadol as an adjuvant to 2% lidocaine for inferior alveolar nerve block shortened the anesthetic action duration and did not improve postoperative analgesia.