Objective: To examine the results of treatment of a surgical site infection (SSI) with a single antibiotic after laparoscopic surgery. Design: Retrospective Study Setting: General hospital Methods: We examined the results of treatment of a surgical site infection by two antibiotic dosage methods. The old group comprised 1,241 cases from April 2005 through March 2010; the new group comprised 870 patients treated from April 2010 through May 2013. The old group received Cefazolin 2g/day (postoperative day 0-1) intravenously (IV) and Cefdinir 300 mg/day orally (postoperative day 2-6). We divided the new group into two dosage methods. New group 1 received Cefazolin 1 g IV one time. New group 2 received Fromoxef 1g IV 6 hours postoperatively and 2 g/day IV daily (postoperative day 1-3) in addition to the dosage given to new group 1. Results: New group 1 comprised 770 cases; new group 2 comprised 100 cases. In the old group, the number of SSIs was 20: 15 (1.2%) superficial incisional SSIs; and 5 (0.4%) deep incisional or organ/Space SSIs. In new group 2, 5 SSIs (0.5%) occurred. Three (0.3%) were superficial and three (0.3%) were deep or organ/space SSIs. Conclusions: We did not note any significant difference in the number of SSIs between the two groups (P = 0.06). We suggest that simplification of antibiotics dosage is possible in approximately 90% of cases. We confirmed that simplification of antibiotic dosage does not increase the risk of a SSI. Accumulation of additional cases would be necessary to strengthen this finding; however, we are of the opinion that the new dosage provided quality medical care and reduced expense.