Septic shock is a major complication of sepsis and is one of the leading causes of admission to intensive care unit (ICU) as well as a major contributor to global mortality, accounting for one in five deaths worldwide and approximately 11 million deaths annually. There is around 530 millions of people living with diabetes, with type 2 diabetes accounting for 96% of these population. Among these patients, septic shock is a major concern, as they are more susceptible to developing infections and have more associated comorbidities. Metformin is the first line oral treatment for type 2 diabete. Beyond its metabolic effects, metformin has pleitropic effects exerting actions on mitochondrial metabolism and immune-inflammatory pathway that could potentially be benefit in septic shock. Several observational studies, converge on a reduction in mortality among patients treated with long-term metformin prior to their admission to the ICU for sepsis or septic shock as well as a reduction in renal dysfunction. Despite these results, the current literature remains highly heterogeneous in its methodology. Most studies focused on patients with sepsis rather than targetting specifically most severe patients with septic shock. Study designs vary widely, most of them are monocentric, some included patients in the emergency departments and others compared type 2 diabetic patients to patients without any history of diabetes making comparisons and generalisation of findings difficult. The main objective of this study was to evaluate the effect of pre-admission metformin exposure in type 2 diabetic patients admitted to the ICU for septic shock on 30-day mortality and on organ failures.