Purpose: The purpose of this study was to identify the effect of the exchange of saline used in surgical procedures on surgical site infections. Method: Patients with stomach cancer were assigned to the experimental group or to the control group by random sampling, respectively. The experimental group received an exchange of saline during the operation right after the excision of the stomach in a gastrectomy but the control group did not. Data were collected from the medical charts of 34 patients from Dec. 1, 2002 through May 31, 2003. Result: The surgical site infection rate of the experimental group was 5.9% while surgical site infection rate of the control group was 17.6%. In total, the surgical site infection rate was 11.8%. The experimental group maintained a normal level of WBC on post operative day 3; however, the control group, showed an increase of WBC on post operative day 3. Conclusion: The exchange of saline used in an operation immediately after the excision of the stomach in a gastrectomy decreases the contamination level of saline used in the operation, and can prevent surgical patients from a surgical site infection.