Measuring progress toward healing is fundamental to the management of pressure ulcers. A method to assess progress of an individual ulcer over time is lacking. Given the limitations of currently available instruments and the need for a precise and practical method of monitoring healing in clinical practice, the National Pressure Ulcer Advisory Panel initiated the development of a new tool for measuring pressure ulcer healing. The key elements in developing an instrument include simplicity of use in clinical settings, validity for measuring whether ulcers are improving or worsening, and sensitivity to changes in the ulcer between observations. A new tool incorporating surface area, exudate amount, and surface appearance is proposed. Content validity, correlation validity, prospective validity, and sensitivity to change can be met by the proposed Pressure Ulcer Scale for Healing instrument.