Objective: The objective of the present study is to evaluate the effect of low intensity pulsed ultrasound therapy on soft and hard tissue healing following surgical removal of impacted mandibular wisdom tooth .Materials and Methods: Twenty-four patients were subjected to surgical removal of impacted mandibular third molar teeth 16 females ,8 males . They divided to two groups , group 1study group in which the operated side was exposed to low intensity pulsed ultrasound stimulation (LIPUS), group 2 control group in which the operated side was left to heal normally without exposure to LIPUS stimulation. Preoperative and postoperative measurements were recorded including; pain using visual analogue scale (VAS), mouth opening utilizing Vernier-calibrated sliding caliper which measuring the inter-incisal distance between the upper and lower incisors at maximum opening, and the facial contour of patients on the impacted side was measured preoperatively as a baseline by measuring the following distances : Tragus- Lip distance and Gonion- External canthus distance. Postoperative clinical evaluation was done every day for VAS and on the 2nd day ,5th and day7th day for trismus and facial swelling . Radiographic evaluation using digital radiographs was performed to measure changes of bone density ofextraction socket at the following intervals: 1week, 1 month and 3 month.