OBJECTIVES: Hypoglycemia is an acute complication of diabetes that increases the morbidity, mortality and disease costs. We aimed to estimate the annual NHS expenditure managing severe hypoglycemia episodes in type 2 diabetic patients in Portugal. METHODS: HIPOS-ER (Hypoglycemia in Portugal Observational Study – Emergency Room) study was an observational, cross-sectional, multicenter, hospital-based study conducted in seven centers of Portugal mainland within a period of 12 months (January 2013 - January 2014). Patient level data were used to quantify healthcare resource consumption related to emergency transportation, emergency department care and hospitalization. Unit costs for 2014 were extracted from official sources and reported in euros. RESULTS: A total of 425,706 admissions at the emergency room were registered in the participating hospitals within the shifts covered by HIPOS-ER study. Of these, 0.074% had diabetes type 2 and were admitted due to an episode of hypoglycemia meaning that theoretically 2.317 emergencies occur yearly in Portugal due to severe hypoglycemia in Type 2 diabetic patients (out of an universe of 3.131.126 annual general emergencies in Portugal). Considering the HIPOS-ER estimated mean cost for managing this type of hypoglycemia (i.e. €1,479), we expect that around 3.4 millions of euros per year are spent in treating this diabetes related complication at emergency rooms of NHS Portuguese hospitals. CONCLUSIONS: Our estimation highlights the potential overall economic burden of severe hypoglycemias in Portugal, meaning that this diabetes-related event must be taken in consideration by different healthcare stakeholders not only from strict clinical point of view, but also from and economic one.  We conclude that severe hypoglycemic events represent a substantial cost for society and in particular for the hospitals of the National Health Service.