Pressure injury is a healthcare problem frequently encountered in nursing homes. This study evaluated the effects of the care delivered under the guidance of a protocol for pressure injury prevention at a nursing home. It was implemented in four phases. In the pre-protocol period, the pressure injury incidence and nurses' care practices were evaluated. In the second phase, nurses were trained to use the protocol. In the third phase, the nurses provided care under the guidance of the protocol (post-protocol period). In the fourth phase, the incidence of pressure injury and nurses' care practices were compared between the pre- and post-protocol periods. The average age of the older residents was 78.40±7.12 years, and all were at high or very high risk of pressure injury according to the Braden scale scores. Some 30% were bed bound; 90% had faecal and urinary incontinence; and 70% had malnutrition. The results showed that the pressure injury incidence reduced from 17.39% in the pre-protocol period to 10.87% in the post-protocol period, while the nurses' care practices improved in the post-protocol period. Thus, use of pressure injury-prevention protocols can reduce the incidence of these injuries in vulnerable care home residents.