OBJECTIVES: Determine nursing home characteristics related to adherence to use of a hip protector (HP) to prevent fracture; also describe adherence and related resident characteristics. DESIGN: A multicenter, randomized controlled trial of a HP in which adherence to wearing the HP was monitored by research staff 3 times a week for up to 21 months; data were collected by interviews and chart review. SETTING: Thirty-five nursing homes in Boston, St. Louis, and Baltimore. PARTICIPANTS: A total of 797 eligible residents, 633 (79%) of whom passed the run-in period, 397 (63%) of whom remained in the study until the end of follow-up. INTERVENTION: Residents wore a single HP on their right or left side. MEASUREMENTS: In addition to regular monitoring of adherence, data were collected regarding facility characteristics, staffing, policies and procedures, perception of HPs and related experience, and research staff ratings of environmental and overall quality; and also resident demographic characteristics, and function, health, and psychosocial status. RESULTS: Facility characteristics related to more adherence were not being chain-affiliated; less Medicaid case-mix; fewer residents wearing HPs; more paraprofessional staff training; more rotating workers; and having administrators who were less involved in meetings. CONCLUSION: Efforts to increase adherence to the use of HPs should focus on facilities with more Medicaid case-mix to reduce disparities in care, and those that have less of a culture of training. Staff may need support to increase adherence, and when adherence cannot be maintained, HP use should be targeted to those who remain adherent. Elsevier Inc. All rights reserved.