IMPORTANCE Falls have been associated with morbidity and mortality in elderly patients. Assessment of frailty at hospital admission may help health care professionals evaluate fall risk in patients with trauma-related injury. OBJECTIVE To determine whether frailty assessed using the Canadian Study of Health and Aging Clinical Frailty Scale is associated with readmission for falls after index admission for trauma-related injury in patients aged 50 years and older. DESIGN, SETTING, AND PARTICIPANTS This retrospective cohort study reviewed the medical records of 804 patients aged 50 years and older with trauma-related injury who were admitted to the University of Iowa Hospitals and Clinics between July 1, 2010, and June 30, 2015. Records were reviewed from May 30 to August 1, 2017, and patient demographics, admission data, injury severity scores, history of falls, and postindex readmission data for ground-level falls were recorded. Frailty scores were calculated using the Canadian Study of Health and Aging Clinical Frailty Scale. Patients with a score of 5 or higher were classified as frail. MAIN OUTCOMES AND MEASURES Frailty assessed using the Canadian Study of Health and Aging Clinical Frailty Scale and readmission for falls after index admission for trauma-related injury. RESULTS A total of 804 patients with trauma-related injury were included in the study. The mean (SD) age was 70 (13.4) years; 744 patients (93.4%) were white, and 380 (47.3%) were men. Among the total population, the mortality rate was 3.7%; 255 patients (31.7%) were classified as frail and 549 (68.3%) as nonfrail. The mean (SD) injury severity score was 9.8 (7.9), and the score was similar between frail and nonfrail patients. Of 255 frail patients, 179 (70.2%) were women, and frail patients were significantly older than nonfrail patients (mean [SD], 79.2 [12.1] years vs 66.2 [11.9] years, respectively; P < .001). The percentages of frail patients presenting to the hospital with a history of falls and readmitted for falls after index admission were higher than those of nonfrail patients (63 [24.8%] vs 53 [9.6%] and 55 [21.6%] vs 58 [10.6%], respectively; both P < .001). Frailty was associated with discharge to the home with health care (odds ratio [OR], 4.82; 95% CI, 2.10-11.01;