Forty-one patients with fractures of the lower jaw and 20 health donors have been examined. Patients with unilateral mandibular fractures received a conventional treatment (group 1) patients with bilateral mandibular fractures received a conventional treatment and immunomodulin (group 2). Results of investigations showed that immunity indices in patients of group 1 at admission to the hospital were in the normal limits, and reduced by the discharge. Immunity findings in patients of group 2 were rather decreased at admission, and normal after use of immunomodulin. Complications in group 2 were less frequent than in group 1.