Background: Sleep disorders are commonly seen in type 2 diabetic patients. However, there is not much research about the association of diabetic complications and poor sleep quality. Objectives: To evaluate diabetic complications and to find out which diabetic complications are associated with poor sleep quality in older diabetic patients treated at National Geriatric Hospital. Methods: A cross-sectional study on 178 older diabetic patients treated at National Geriatric Hospital from March to October, 2020. Quality of sleep was assessed using the Pittsburgh Sleep Quality Index. Results: 93 patients (52.2%) had peripheral nerve complications. 50% patients had diabetic retinopathy. There were 86 patients (48.3%) had experienced hypoglycemia in the last 3 months. The prevalence of diabetic neuropathy, cerebral vascular disease, cardiovascular disease, peripheral artery disease and foot complication were 12.9%; 12.9%; 9%; 8.4% and 7.3%, respectively. 19.1% patients didn’t have any complications of diabetes. Patients with diabetic retinopathy and cerebral vascular disease had a significantly higher rate of poor sleep quality compared with the group without these complications. There were no significant association between diabetic nephropathy, cardiovascular disease, peripheral nerve complication, foot complication, hypoglycemia and sleep quality. Conclusion: This study showed that older diabetic patients had many complications. Diabetic retinopathy and cerebral vascular disease were higher in the poor sleep quality group.