Diabetic foot ulcer is one of the chronic complications of diabetes mellitus which occurs on average 10 years after the onset of diabetes mellitus. Patients with diabetes mellitus which lack control of their blood sugar will be more susceptible to this complication because the blood circulation is disrupted due to high blood sugar levels. Ulcers experienced by patients will cause pain and discomfort that can be bad for the sleep quality of patients. This study identified the correlation between the severities of ulcers with sleep quality among diabetic foot ulcer patients. Design of this study is analytical with cross sectional approach. Seventy-three patients with diabetic foot ulcer were participated and interviewed by a purposed sampling technique in clinic of RUMAT wound care. The respondent interviewed using a Pittsburgh Sleep Quality Index (PSQI) questionnaire to measure the patient's sleep quality and Wagner's wound assessment to measure severity foot ulcer. The results were analyzed using Chi square test and showed a significant correlation between ulcer severity and sleep quality among diabetic foot ulcer patient's (p = 0.004; α = 0.05). Odds ratio for patients with severe ulcer had 5.2 times more risk to have poor sleep quality than patients with mild severity ulcer (95% CI OR: 1.78; 15.47). The research recommended to improving wound care quality for better sleep quality among diabetic patients.