Hypoglycemia is one of the limiting factors for achieving adequate metabolic control in diabetic patients. Although it is well accepted that the economic burden of diabetes is substantial, the financial impact of hypoglycaemia to patients, the health system and society is unclear. OBJECTIVES: To assess the economic impact associated with hypoglycemic events through a search of the published literature in type 1 and type 2 diabetic patients using oral antidiabetes drugs and/or insulin therapy. METHODS: An in-depth literature review was conducted, EMBASE and PubMed databases were searched from 2005 to November 2011. A total of 24 US and European articles were retrieved. Costs were collected according to severity of hypoglycemia: symptomatic non-severe and severe hypoglycemia. RESULTS: Direct non-medical costs and indirect costs are studied for symptomatic non-severe hypoglycemia, as the economic impact is limited to lost work productivity, increased out-of-pocket costs mainly due to groceries, extra test strips and transportation services. The lack of consensus of the definition of severe hypoglycemia leads to great variation of published costs. Total costs per severe episode (direct/indirect costs), for patients requiring assistance from family members ranged from 30 to 63€, for patients needing medical attention but not admitted to hospital overnight ranged from 274 to 489€, and for patients requiring hospitalization ranged from 1306 to 3917€. US Study reported mean cost per severe episode of $1087.  CONCLUSIONS: No clear consensus on the definition of severity of hypoglycemia was specified in the literature. Costs for symptomatic or non-severe hypoglycemia are sparse and a high variation in costs for severe hypoglycemia was observed. Hospitalization costs are the main cost driver for severe events. The evaluation of the economic burden of severe hypoglycaemia needs to consider the subcategories of assistance in order to reduce uncertainty in third payer point of view.