<b><i>Introduction:</i></b> Uncontrolled glycemia is a well-recognized predictor of severity and deaths in previous respiratory viral outbreaks. We aimed to describe the characteristics and clinical course of patients with diabetes admitted with COVID-19 infection at a tertiary care center in the Emirate of Dubai, UAE, and assess the impact of hyperglycemia on the clinical outcomes. <b><i>Methods:</i></b> This study is a single-center, observational, retrospective chart review of 250 cases during the months of March to May 2020. <b><i>Results:</i></b> Among the 250 cases studied, 235 (94%) were male. The mean age of the study group was 49.6 ± 10.4 years, with an age range of 21–78 years. Diabetes was previously known in 166 (66.4%) of the patients. The mortality (<i>p</i> = 0.03) and requirement for mechanical ventilation (<i>p</i> = 0.02) were higher for the cases with newly diagnosed diabetes when compared to those with pre-existing diabetes. <b><i>Conclusion:</i></b> Uncontrolled hyperglycemia adversely affects patients with COVID-19 infection. Newly diagnosed and previously undiagnosed hyperglycemia poses an added risk for complications. In the context of the COVID-19 pandemic, optimizing glycemia in hospitalized patients is of paramount importance and screening to detect undiagnosed cases of diabetes may be particularly relevant.