AIM: Hypoglycaemia is considered a factor contributing to morbidity and mortality in patients with diabetes. The aim of the present study was to examine the frequency, clinical characteristics, predisposing factors and outcomes of iatrogenic hypoglycaemia requiring medical assistance.METHODS: Eight hospitals participated in this prospective survey of documented iatrogenic hypoglycaemia at their emergency departments. Cases with type 2 diabetes (T2D) were compared with a control group, consisting of patients visiting the outpatients' diabetes clinics of the same hospitals during the same time period.RESULTS: Median survey duration was 16.5 months, and 295 episodes of iatrogenic hypoglycaemia were recorded. Frequency varied across centres from 0.25 to 0.78 cases per 100 presenting patients. Most cases (90.8%) were observed in patients with T2D (mean age: 76.7±10.1 years), while 8.1% of events were recorded in patients with type 1 diabetes (mean age: 42.7±18.3 years). Total in-hospital mortality was 3.4%, and all involved patients with T2D. In T2D patients, advanced age (OR: 1.3 [1.20-1.45] for 5-year increase), use of sulphonylureas (OR: 4.0 [2.5-6.36]), use of insulin (OR: 2.35 [1.42-3.95]), lower estimated GFR (OR: 1.15 [1.07-1.23] at 10mL/min) and number of comorbidities (OR: 1.74 [1.34-2.27]) were each independently associated with hypoglycaemia requiring medical assistance.CONCLUSION: Hypoglycaemia requiring medical assistance in patients with diabetes is a moderately common condition seen in emergency departments and has a mortality rate of 3.4%. The majority of cases involve elderly individuals with T2D who are suffering from serious comorbidities and treated with insulin and/or sulphonylureas.