Objective To investigate the prevalence of geriatric syndrome in the hospitalized elderly with diabetes mellitus. Methods A total of 213 elderly patients at an age of over 65 years with type 2 diabetes mellitus admitted in our department from July 2012 to September 2014 were enrolled in this study. Each subject was assessed for cognitive impairment, mood, sleep problems, falls risk, urinary incontinence, nutrition risk, and impairment of activity of daily living within 48h after admission. Results The cohort was at an age of (74.7±6.6) years, with a duration of diabetes for (12.4±8.9) years (median 10 years), and with 3 to 27 types of comorbidities. They averagely had (3.3±1.7) geriatric syndrome. Sixty percent of them had polypharmacy, and 40% to 50% had impairment in activities of daily living. The prevalence of cognitive impairment, emotional disorder, chronic pain and high risk of falling was 39.0%, 29.0%, 31.9% and 43.0%, respectively. The incidence of falling risk was higher in the patients with longer disease course [54.8% (course＞10 years) vs 37.9% (course≤10 years)]. When compared with the well-controlled diabetic patients (HbA1c ≤7.5%), the poor-controlled patients (HbA1c＞7.5%) were found to have longer disease course [(17.7±10.5) vs (10.9±7.7) years], higher risk rate of falling (61.7% vs 38.5%), and higher incidences of sleep disorder (51.1% vs 34.9%), but lower incidence of cognitive impairment (27.6% vs 44.8%; all P＜0.05). Conclusion The elderly with diabetes mellitus have high risks of cognitive impairment, emotional disorder, chronic pain and falling risks. We need to make comprehensive geriatric assessment and individualized intervention for them.