The coronavirus disease 2019 (covid-19) pandemic has caused a public health emergency worldwide. Risk, severity and mortality of the disease have been associated with non-communicable chronic diseases, such as diabetes mellitus. Accumulated evidence has caused great concern in countries with high prevalence of this morbidity, such as Brazil. This text shows the picture of diabetes in Brazil, followed by epidemiological data and explanatory hypothesis for the association between diabetes and covid-19. We emphasized how the burden of these two morbidities in a middleincome country has aggravated this pandemic scenario. The comprehension of this association and biological plausibility may help face this pandemic and future challenges.