Interest rates being similar and assuming that you are making the required and/or minimum payments on all debt every month, you will generally want to work on paying off the revolving debt first. First, it is important to use no more than 25% of your revolving credit maximum in any given month to avoid hurting your credit score, so getting and keeping the revolving debt low is important. There is no similar restriction on installment debt. Second, the interest rate on your revolving debt could go up based on your credit score, whereas the interest rate on installment debt is fixed.