OBJECTIVES: Diabetes has been shown to be a risk factor for corona virus disease-2019 (COVID-19) infection. The characteristics of patients with diabetes vulnerable to this infection are less specified. We aim to present the characteristics of patients with diabetes admitted to hospital with COVID-19. DESIGN: A retrospective case series. SETTING: A single clinical centre in the UK. METHODS: We have retrospectively collected the demographics, medical characteristics and outcome of all patients with diabetes admitted to hospital over two-week period with COVID-19 infection. All cases were diagnosed by a reverse transcription polymerase chain reaction (RT-PCR) of pharyngeal and nasal swabs. RESULTS: A total of 71 COVID-19 patients were admitted during the study period of whom 16 (22.5%) patients had diabetes and were included in this case series. There was no significant difference between patients with compared to those without diabetes regarding age, gender or clinical presentation. However, comorbidities were more common in patients with diabetes specially hypertension {75% v 36.4%, a difference of 38.6%, 95% confidence interval (CI) 6.5-58.3} and chronic kidney disease (37.5 v 5.5, a difference of 32% (1.6-51.6). Patients with diabetes were significantly more obese than those without diabetes (56.2% v 21.8% a difference of 34.4%, 95% CI 7.7-61.1). About one third (31.3%) of patients with diabetes were frail. Mean {standard deviation (SD)} duration of diabetes was 10 (2.8) years and mean (SD) HbA1c was 60.3 (15.6) mmol/mol. The use of angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs) and non-steroidal anti-inflammatory drugs (NSAIDs) was common (37.5%, 25% and 18.8% respectively). There was no significant difference in the outcomes between patients with compared to those without diabetes. CONCLUSION: Patients with diabetes hospitalised for COVID-19 were significantly more obese and had high prevalence of comorbidities than those without diabetes. Other features of patients with diabetes and COVID-19 infection included long duration of diabetes, less tight glycaemic control and common use of ACE inhibitors, ARBs and NSAIDs.