Importance. Conventionally, treatment goals for diabetic patients primarily target glycemic levels and traditional cardiovascular risk factors (blood pressure, lipids) control to reduce macro- and micro-vascular complications. More recently, the relevance of assessing functional status in older diabetic patients has emerged. A knowledge gap exists regarding the risk of functional dependency in older diabetic patients and on the impact of Comprehensive Geriatric Assessment (CGA) on the achievement of easily calculated and objective patient-centered outcomes. Objective To investigate if a personalized plan of care base on CGA would reduce the risk of functional decline over time in older patients with diabetes as compared to usual care Design. Individual patient randomized controlled trial comparing intervention with usual care. Setting. Three hospitals in Cagliari, Ferrara, and Milano, Italy. Participants. One-hundred and eighty diabetic patients aged ≥75 years. Intervention. Usual care for both the Control and Intervention groups will be assured by a diabetologist according to in-use guidelines. After randomization, a geriatrician will administer a thorough CGA to all participants allocated to the intervention groups. CGA will be used to identify specific treatment goals according to the functional status of the patient and to incorporate Patient-preferred outcome in the management of diabetes and comorbidities. Using the results of the CGA the geriatricians along with the attending diabetologist and additional healthcare professionals, if needed, will implement a personalized diagnostic and therapeutic plan of care. Participants in the Control group will receive no additional intervention over and above usual care. Follow-up. Follow-up visit will be scheduled at 6 and 12 months after randomization. Main outcome measures. The primary outcome will be represented by the change in physical performance, assessed by change in the Short Physical Performance Battery (SPPB) score over time. Secondary outcomes will be represented by change in cognitive function, sarcopenia, dependency, glycated hemoglobin levels, and rate of hospitalization as well as Time-at-home. Expected Results. The CGA-driven intervention applied to older diabetic patients will have significant benefits on functional outcomes as compared to usual care. Implications. Multimodal intervention in older diabetic patients will significantly impact on the ageing population and allow a novel process to be developed for interventions that produce the maximum disability-free life years lived combined with the highest quality of life for this vulnerable and often neglected group of adults.