Purpose: Most surgeons administer prophylactic antibiotics for 3 to 5 days postoperatively. However, the Center for Disease Control (CDC) guideline recommends antibiotic therapy for 24 hours or less in clean/uncontaminated surgery. Thus, we prospectively studied the use of short term prophylactic antibiotic therapy after gastric cancer surgery. Materials and Methods: A total of 103 patients who underwent gastric cancer surgery between October 2007 and June 2008 were prospectively enrolled in a short term prophylactic antibiotics program. One gram of cefoxitin was administered 30 minutes before the incision, and one additional gram was administered intraoperatively for cases with an operation time over 3 hours. Postoperatively, one gram was administered 3 times, every 8 hours. Patients were checked routinely for fever. All cases received open surgery, and the surgical wounds were dressed and checked for Surgical Site Infection (SSI) daily. Results: Of the 103 patients, 15 were dropped based on exclusion criteria (severe organ dysfunction, combined resection of the colon, etc). The remaining 88 patients were included in the short-term program of prophylactic antibiotic use. Of these patients, SSIs were detected in 8 (9.1%) and fever after 2 postoperative days was detected in 11 (12.5%). The incidence of SSIs increased with patient age, and postoperative fever correlated with operation time. Conclusions: Short term prophylactic antibiotic usage is feasible in patients who undergo gastric cancer surgery, and where there are no grave comorbidities or combined resection.