Diabetes mellitus is the commonest endocrine and metabolic disorders. Patients with diabetes have about double risk to develop severe COVID-19. The severity of COVID-19 shown to be associated with dysregulation of glycemic control in diabetes. This review focus on the most obvious contributing factors linking these nowadays the two common pandemics. A broad literature search been performed on Google Scholar and PubMed for the periods between 01/01/2021 and 01/03/2021. The search includes the followings key words; diabetes, COVID-19, SARS-CoV-2, corona virus, ACE2 and cytokines storm. Hyperglycemia and insulin resistance in diabetes patients acts as independent risk factors for acquiring severe covid-19 complication. ACE2 expression in diabetic patients is reduced but this reduction wasn’t protective for gaining COVID-19 and even worsening the patient’s outcomes. Exaggerated inflammatory responses in diabetics towards COVID-19 is obvious and serves to transform cytokines storm to a “Cytokine Super Cyclone”. Both COVID-19 and diabetes mellitus affects each other and patients with diabetes subjected to have severe COVID-19 and with an increasing risk of mortality and worsening outcome. Diabetic persons should take great attention to keep their glycemic control as ideal as possible and it is essential to put them in the high priority list for gaining vaccination against COVID-19 virus.