Background: Third molar surgey always needs primary intervention as it can lead to various complications and pathologies. Considering other ways for postoperative anesthesia it was infered that submucosal group which showed simple injection technique and direct surgical site administration is more beneficial. It was noticed as a patient comfort method which can be the preferred as the drug of choice over intravenous route of dexamethasone injection. Introduction: Impaction of third molar is a common affliction and surgical removal is the only treatment option. The post-operative sequelae following the third molar surgery are pain, edema and trismus. The use of corticosteroids is to counteract it via various routes. Still, controversy exists in the literature regarding the administration of corticosteroids over the routes and time of administration. The purpose of this study was to compare the postoperative pain, edema and trismus following third molar surgery while using preoperative intravenous and submucosal routes of dexamethasone, in terms of pain, facial swelling, and trismus. Materials and Methods: This study consisted of 64 patients presented with mesioangular impacted mandibular third molar for surgical removal. Preoperative measurements of edema, trismus were analyzed. Postoperative pain was estimated using visual analogue scale. Edema was assessed by the extra oral facial measurements. Trismus was measured by recording the interincisal opening in millimeters. Dexamethasone was administered intravenously or submucosally according to the choice of operating surgeon and were divided into 2 groups. Results: Mean and standard deviation calculated for continuous variables. Changes in parameters was analysed using t test and Mann–Whitney U test. Here, submucosal group were reported with increased pain on the second postoperative day. On seventh postoperative day mean value turns to 0.7 ± 1 for submucosal and 0.6 ± 1.2 for intravenous group. On overall observation, intravenous group expressed statistically significant ( P < 0.01) reduction in pain compared to the submucosal group during immediate and second postoperative days. Conclusion: Analyzing the previous studies, and from the experience of the present one, it could be reasonably found out that administration of submucosal dexamethasone is beneficial for overall patient compliance.