This study aimed to evaluate the effectiveness of the delirium prevention interventions recommended by the Delirium Prevention Guidelines for Elderly Stroke Patients (DPGESP). The DPGESP comprises nine dimensions with 28 interventions, including risk factor assessment, orientation disorder prevention, sleeping pattern maintenance, sensory interventions, constipation, dehydration, hypoxia and infection prevention, pain management, and appropriate nutrition maintenance. This quasi-experimental study used a nonequivalent control group and a pretest–posttest design. The experimental and control groups each included 54 patients, and the participants were elderly patients who were admitted to the stroke unit. The study outcomes were the delirium incidence and severity, stroke impact, and length of hospitalization. Posttest values for delirium incidence, severity, stroke impact, and length of hospitalization were significantly improved in the experimental group. Implementation of the DPGESP had beneficial effects on the delirium incidence and severity, stroke impact, and length of hospitalization among elderly patients admitted to a stroke unit.