BACKGROUND AND AIMS: We describe the characteristics and short-term prognosis of in-patients with diabetes and COVID-19 admitted to a Belgian academic care center. METHODS: We retrospectively reviewed the data on admission from patients with known or newly-diagnosed diabetes and confirmed COVID-19. First, survivors were compared to non-survivors to study the predictive factors of in-hospital death in patients with diabetes. Secondly, diabetic patients with SARS-CoV-2 pneumonia were matched for age and sex with non-diabetic patients with SARS-CoV-2 pneumonia, to study the prognosis and predictive factors of in-hospital death related to diabetes. RESULTS: Seventy-three diabetic patients were included. Mean age was 69 (±14) years. Women accounted for 52%. Most patients had type 2 diabetes (89.0%), long-term complications of hyperglycemia (59.1%), and hypertension (80.8%). The case-fatality rate (CFR) was 15%. Non-survivors had more severe pneumonia based on imaging (p 0.029) and were less often treated with metformin (p 0.036). In patients with SARS-CoV-2 pneumonia, CFR was 15.6% in diabetic (n = 64) and 25.0% in non-diabetic patients (n = 128), the difference being non-significant (p 0.194). Predictive factors of in-hospital death were elevated white blood cells count (HR 9.4, CI 1.50-58.8, p 0.016) and severe pneumonia on imaging (HR 25.0, CI 1.34-466, p 0.031) in diabetic patients, and cognitive impairment (HR 5.80, CI 1.61-20.9, p 0.007) and cardiovascular disease (HR 5.63, CI 1.54-20.6, p 0.009) in non-diabetic patients. CONCLUSION: In this monocentric cohort from Belgium, diabetic in-patients with COVID-19 had mostly type 2 diabetes, prevalent hyperglycemia-related vascular complications and comorbidities including hypertension. In this cohort, the CFR was not statistically different between patients with and without diabetes.