Prevention of pressure ulcers is fundamental to safe care of nursing home residents yet the role of hydration in pressure ulcer prevention has not been systematically examined. This randomized clinical trial was undertaken to determine whether administration of supplemental fluid to nursing home residents at risk for pressure ulcers would enhance collagen deposition, increase estimated total body water, augment subcutaneous tissue oxygenation, and was safe. After a baseline period, 64 subjects were randomized to receive the fluid volume prescribed or additional fluid (prescribed plus 10 mL/kg) for 5 days. Participants' potential to heal as measured with hydroxyproline was low at baseline and did not increase significantly during treatment when additional fluid was systematically provided. Fluid intake increased significantly during treatment. Estimates of total body water and subcutaneous oxygen did not increase, indicating hydration was not improved. Supplemental fluid did not result in overhydration as measured by clinical parameters. Further work is needed to examine the relationship between fluid intake and hydration in nursing home residents as well as the role of hydration in pressure ulcer prevention.