Impacted mandibular 3rd molar is most common in younger adults and the patient seeks treatment whenever there is pain, swelling or any other discomfort such as sensory disturbances. Although the rate of complication is low, the efforts to limit intraoperative or postoperative complications may have a great impact in terms of enhancing patient outcome. Mandibular Impacted third molar are in close proximity to the inferior alveolar nerve, lingualnerve, mylohyoid nerve and buccal nerves. Each of these nerves is at risk of damage during surgical removal of mandibular third molar, but the most troublesome complications result from inferior alveolar or lingual nerve injuries. The majority of these injuries results in transient sensory disturbance but, in some cases, permanent paraesthesia (abnormal sensation), hypoaesthesia (reduced sensation) or, even worse, some form of dysaesthesia (unpleasant abnormal sensation) can occur. This paper reviews the lingual nerve injury after surgical removal of mandibular third molar and how to prevent from lingual nerve injury.