OBJECTIVE:To describe a new observational scale, the Sessing scale, for measuring the progression of pressure ulcers.CRITERION STANDARDS:Changes in Shea stage and the diameter of healing pressure ulcers.SUBJECTS:A cohort of 84 nursing home residents with pressure ulcers.RESULTS:There were strong relationships between changes in healing as measured by the Sessing Scale and those measured by the Shea Scale (Spearman'sr= 0.90;P<.0001), and between changes in the Sessing scale compared with changes in ulcer diameter (Spearman'sr= 0.64;P<.001). Test‐retest reliability was good (Kappa = 0.84) in a sample of 50 subjects.CONCLUSION:The Sessing scale is a simple, easy to use, observational instrument with validity and reliability for the assessment of progression of pressure ulcers in a clinical or research setting. Findings indicate that the Sessing scale, with its description of granulation tissue, infection, drainage, necrosis, and eschar, measures an important domain of wound healing that is independent and perhaps as important to clinicians and researchers as either Shea stage or ulcer siz