The objectives of this study were to evaluate the impact of a collaborative model of quality improvement in nursing homes on processes of care for the prevention and treatment of pressure ulcers. The study design was experimental. We studied 29 nursing homes in New Jersey, Pennsylvania, and Rhode Island. Participants consisted of pressure ulcer quality improvement teams in 29 nursing homes. Quality improvement teams attended a series of workshops to review clinical guidelines and quality improvement principles and to share best practices, and worked one-on-one with mentors to implement quality improvement techniques and to collect data independently. We calculated process measures based on the Agency for Healthcare Research and Quality (AHRQ) guidelines. Process measures addressed each facility's processes of care for the prevention and treatment of pressure ulcers at baseline and after 12 months of intervention. Prevention measures focused on recent admissions and high-risk residents; treatment measures focused on patients newly diagnosed with pressure ulcers and all patients with pressure ulcers. Overall, 6 of 8 prevention process measures improved significantly, with percent difference between baseline and follow up ranging from 11.6% to 24.5%. Three of 4 treatment process measures improved significantly, with 5.0%, 8.9%, and 25.9% difference between baseline and follow up. For each process measure, between 5 and 12 facilities demonstrated significant improvement between baseline and follow up, and only 2 or fewer declined for each process measure. Improvement in processes of care after the use of a structured collaborative quality improvement approach is possible in the nursing home setting.