Aqua oxidation water is a new disinfectant with a bactericidal activity based on high oxidation-reduction potential and acidity. We compared the effectiveness of aqua oxidation water and povidone iodine against the surgical site infection (SSI). The bacteriological effect against several organisms and the efficacy of both disinfectants were almost similar. However, the duration of treatment with aqua oxidation water was shorter than that with the povidone iodine in healed wounds (p<0.05) and the number of patients treated with aqua oxidation water who reported pain was smaller than that with povidone iodine (p<0.05). Our results indicated that aqua oxidation water useful and effective for the treatment of incurable SSI.