The purpose of this study was to determine the effect of range of motion exercises on preventing delirium and shortening the duration of delirium among patients in the intensive care unit who are aged 65 and over. The study was conducted in the intensive care unit on patients with non-invasive mechanical ventilation. The sample size included 47 patients from the intervention group and 47 from the control group. The incidence of delirium was 8.5% in the intervention group and 21.3% in the control group. The duration of delirium was 15 h for patients in the intervention group and 38 h for those in the control group. Although delirium incidence and duration decreased by 2.5-fold in the intervention group compared to the control group; there was no significant relationship between the intervention and control groups. In conclusion, as the decreases in delirium occurrence and duration were not statistically significant, the effect of range of motion exercises was limited. (C) 2015 Elsevier Inc. All rights reserved.