Postoperative infections are common complications of obstetric and gynecologic surgery. The pathophysiology of both postcesarean endometritis and postoperative cuff cellulitis involves the ascending spread of potentially pathogenic microorganisms found in the vagina. Bacterial vaginosis is associated with increased vaginal concentrations of certain anaerobic and facultative bacteria. Bacterial vaginosis appears to be a risk factor for the development of postoperative infections in obstetrics and gynecology.