In order to determine current beliefs concerning the relevance of breast mammographic percent density (MPD) as a surrogate marker for breast cancer, the panel and the delegates completed a questionnaire. There was general agreement between the panel and delegates on most aspects, although the delegates were unsure whether high breast MPD is a contraindication for hormone therapy and tended to err on the side of caution in suggesting that estrogen and estrogen/progestogen therapy should be stopped before screening mammography. The overall consensus of the panel and the delegates was that breast MPD should become an important clinical tool, and that carefully designed studies are needed to determine exactly how it can be best used to guide clinical decision-making.