A randomized prospective study of 30 patients was undertaken to evaluate antibiotic prophylaxis for orthognathic surgery. Perioperative, high-dosage antibiotic administration was compared to an existing prophylactic regimen employing longer intervals and continued postoperative antibiotics for 7 to 10 days. No significant difference was found between the two groups with respect to incidence of infection. Other variables studie d included gender and age of patients, type of surgery performed, procedure length, and use of fixation.