Monochromatic light has been used in many studies and indicated that phototherapy might be effective in the treatment of pain relief. The aim of this investigation was to evaluate the efficacy of monochromatic light phototherapy on patients who had undergone impacted third molar surgery. Sixty adult patients were included in the study. The patients were divided into 2 groups; the Biolight therapy group and the placebo therapy group. All the subjects received phototherapy 6 minutes preoperative and 10 minutes postoperative. They were examined 3 and 7 days after surgery to evaluate postoperative pain and wound healing. One patient was excluded from the study due to extraction of the third molar in maxilla. All the patients received a questionnaire to answer regarding pain and the number of pain killers consumed. The results from this study showed that Phototherapy using monochromatic light Biolight therapy had no significant differences compared to the placebo group.