We analyzed prospective data from 19 889 elderly residents of 51 nursing homes from 1984 to 1985 to determine the prevalence, incidence, and natural history of pressure ulcers. Among all residents admitted to nursing homes, 11.3% possessed a stage II through stage IV pressure ulcer. For those residents admitted to the nursing home without pressure ulcers during the study period, the 1-year incidence was 13.2%. This increased to 21.6% by 2 years of nursing home stay. People already residing in a nursing home at the start of the study had a 1-year incidence of 9.5%, which increased to 20.4% by 2 years. Pressure ulcers were associated with an increased rate of mortality, but not hospitalization. Longitudinal follow-up of residents with pressure ulcers demonstrated that a majority of their lesions were healed by 1 year. Most of the improvement occurred early in a person's nursing home stay. Although nursing home residents with pressure ulcers have a higher mortality, with good medical care pressure ulcers can be expected to heal.