Background: The postoperative sequelae after third molar surgery include pain, swelling and trismus, Magnesium has antinociceptive effects that can prevent central sensitization caused by peripheral nociceptive stimulation by blockingthe N-methyl-D-aspartate-type glutamate receptors.Studies haveinvestigated Magnesium for postoperative pain relief. This study was aimed to evaluate the efficacy of oral Magnesium lozenge given 30 min before surgery on reducing postoperative sequelae. Method: We recruited 70 patients, randomly assigned to two groups: Magnesium and Control group, groups received lOOmg Magnesium lozenge, placebo lozenge 30 min before surgery respectively and every 6h till 72h after surgery. Third molar extraction was performed under local anesthesia. After extraction, pain, swelling, and mouth opening in both groups observed till 72h. Statistical Analysis: Preoperative and postoperative measurement of visual analog scale scores for pain, edema, interincisal opening, was analyzed using Student t test or ANOVA, Chi-square or Mann-Whit^ney U test was performed for non-parametric samples. P < 0.05 was considered as statistically significant Results: The overall incidence of Pain in the Magnesium group was18% compared to 43% in the Control group (P = .003) Incidence of Pain, swelling, and mouth opening at different time intervals 6h, 24h, 48h and 72h were significantly (P >0.05) better in Magnesium group. Conclusion: Oral Magnesium lozenge administered 30 minutes preoperatively can significantly reduce postoperative sequelaeafter third molar extraction. Keywords: Postoperative sequelae; Third molar; Magnesium.