Introduction: Low-level laser therapy (LLLT) can promote and accelerate the tissue regeneration as it causes the early healing of extraction sockets but the accurate mechanism is unknown. Aim: The study aimed to evaluate the effect of LLLT which was applied in a single session immediately after odontectomy of impacted lower wisdom tooth on pain, swelling, and trismus. Patient and Methods: This study was done on 24 healthy patients who required surgical extraction of impacted lower third molar. The patients were randomly selected and randomly divided into two equal groups, each consisted of 12 patients for group, group I received LLLT immediately after surgical extraction of impacted lower third molar, group II was subjected to routine surgical extraction of impacted lower third molar without application of LLLT. LLLT was applied at ten points: four intra-oral beside to the extracted socket and six extra-oral along the masseter muscle. Laser energy was applied at 100mW for a total of 150 sec, 15 sec for each point. Results: The results showed the effect of a single session of LLLT in control of postoperative pain on the day of surgery and reduction of swelling and trismus after surgical removal of impacted lower third molars (p < 0.05). Conclusion: LLLT could represent a viable tool to control pain in patients who are contraindicated to the medications.