Objective This study aimed to evaluate the effect of low-level laser therapy (LLLT) applied before mandibular third molar extractions on postoperative pain, swelling, and trismus. Materials and methods The study included 28 patients aged 18-45 years with bilaterally impacted mandibular third molars in similar positions, indicated for extraction based on clinical and radiographic examinations. Patients were divided into two groups: Group 1 received LLLT 10 min before surgery, while Group 2 (control group) underwent routine impacted tooth extraction after applying blue LED light. Measurements were taken preoperatively and at 24 h (T0), 48 h (T1), and 7 days (T2) postoperatively to assess the effects of LLLT on pain, swelling, and trismus. Statistical analysis was performed using the Jamovi 2.2.5 software. Due to the non-normal data distribution, the Friedman test was used for repeated measures within groups, while the Mann-Whitney U test was employed to compare the laser and control groups. Results The study included 23 female (82.14%) and 5 male (17.86%) patients, with a mean age of 21.34 +/- 4.37 years. No statistically significant differences were observed between the laser and control groups concerning pain, trismus, and swelling at T0, T1, and T2 (p > 0.05). Conclusion Within the limitations of this study, preoperative LLLT showed clinically acceptable effects on postoperative pain, swelling, and trismus. Further clinical studies are needed to evaluate the long-term success of LLLT.