Objective: As society ages, managing people with diabetes gains importance and becomes difficult because of accompanying diseases and complications. This study examined the effects of treatment changes in people with diabetes over 65. Methods: The data of patients aged ≥65 who were followed up in the İstanbul University, İstanbul Faculty of Medicine between 2010 and 2017 were retrospectively analyzed. Demographic data, comorbidities, complications, and metabolic effects of treatment changes were evaluated. Results: The study included 250 patients with a mean age of 72.0±6.6 years. Of the patients, 78.8% had hypertension, 58.4% had dyslipidemia, 32% had coronary artery disease, and 10% had chronic renal failure. The frequency of diabetic neuropathy was 26%, nephropathy 22.8%, and retinopathy 20.8%. The incidence of hypoglycemia was 16.4%. While oral antidiabetic drugs (OAD) alone decreased by 19%, 14% of these patients switched to OAD + basal insulin therapy and 4% to basal-bolus therapy during the follow-up period. With the addition of basal insulin to OAD, an additional 0.9% reduction in glycated hemoglobin (HbA1c) was achieved, and a further 1.2% reduction was achieved by switching to basal-bolus insulin. Conclusion: Our study has shown that continuing the use of metformin in older adults with diabetes with preserved renal functions and adding insulin to their existing treatments when needed, despite all the reservations, provides an effective treatment by decreasing the HbA1c level. However, the lower-than-expected hypoglycemia frequency in our study may be due to the progressive age of diabetes and hypoglycemia unawareness due to accompanying autonomic neuropathy. Education of patients gains importance in this regard.