Objectives: This study was conducted in order to assess the efficacy of 1st generation cephalosporin as use as a single-dose preoperative prophylactic antibiotic for surgical wound infections resulting from intra-oral bone grafting procedures. Materials and Methods: A total of 23 patients who were to undergo intra-oral bone graft procedures participated in this study. After randomization, 2 grams of 1st generation cephalosporin was orally administered to both the experimental and placebo groups one hour prior to surgery in a double-blind fashion. Post-operatively, the experimental group (12 patients) was orally administered placebo three times a day for three days. The control group (11 patients) was orally administered 1st generation cephalosporin three times a day for three days. The postoperative course was observed for one month including the clinical parameters associated with infection. Results: Postoperative infections were noted in 1 out of 11 patients in the experimental group. No infections occurred in the control group. Conclusion: There was no significant difference in the incidence of postoperative infections between the two groups. Two grams of 1st generation cephalosporin administered orally one hour before surgery served as an effective prophylactic antibiotics therapy for intra-oral bone graft surgery.