OBJECTIVE: The purpose of this study is to compare costs of 3 strategies for women undergoing hysterectomy: (1) test all patients for bacterial vaginosis; treat if positive; (2) treat all patients for bacterial vaginosis; (3) neither test nor treat patients for bacterial vaginosis. For comparison purposes, a fourth strategy is examined: (4) no surgical site infection prophylaxis or bacterial vaginosis treatment. STUDY DESIGN: A cost minimization model was created using estimates obtained from the published literature, Medicare reimbursement data, and wholesale drug costs. RESULTS: In the base case, the optimal strategy was to treat all patients for bacterial vaginosis, with a cuff infection rate of 4.0% and mean cost of $593. The "test all patients for bacterial vaginosis; treat if positive" strategy was also inexpensive, with a mean cost of $623 and 4.2% cuff infection rate. "Neither test nor treat patients for bacterial vaginosis" and "no surgical site infection prophylaxis or bacterial vaginosis treatment" were more expensive and less effective than other strategies. CONCLUSION: This model suggests that consideration should be given to adding metronidazole to standard surgical site infection prophylaxis before hysterectomy.