Background: Patients with diabetes mellitus infected with the new coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are at risk of high morbidity and mortality. Objective: Our study aimed to address the clinical, laboratory and radiological predictors of hospital admission course for patients with diabetes mellitus with COVID19 infection at the time of admission. Patients and Methods: This was a single center, retrospective study of patients with diabetes mellitus (DM) admitted with COVID-19 infection. Patients with unfavorable admission course were compared with those of favorable course regarding patient characteristics, clinical presentation, results of laboratory investigations and chest CT severity score. Univariate and multivariate analysis associated with the unfavorable course was performed. Results: Among 141 patients with DM admitted with COVID19, 44 patients had unfavorable course. Those with the favorable course were significantly younger (53.3±16.4) vs (67.3 ±15.8) in the unfavorable course group, multivariate analysis revealed that age more than 65, presence of hypertension, CT severity scoring, high HBA1c, AST, IL6, oxygen saturation less than 93% and low lymphocyte count were the independent predictors of the unfavorable hospital admission course. Conclusions: Our finding suggests that old age, presence of hypertension, hypoxia at presentation, in addition to high HBA1c, AST, IL6, CT severity scoring and low lymphocyte count were significant predictors of unfavorable admission course in COVID19 patients with diabetes.