Background and aim <p>Thiamine is becoming increasingly common in emergency medicine and is already incorporated into some algorithms for paramedics. This article aims to provide a&#xa0;concise overview of the mechanism of action and indications for thiamine in clinical and preclinical emergency medicine.</p> Materials and methods <p>Current guidelines and study results on the subject were reviewed, combined with physiological and pathophysiological considerations.</p> Results <p>Thiamine deficiency presents with numerous, sometimes nonspecific, cardiovascular and neurological symptoms and may occur in the context of other conditions such as hypoglycaemia, alcohol dependence or severe malnutrition or undernutrition.</p> Discussion and conclusion <p>Given the favourable risk–benefit profile, the indication for intravenous or intramuscular administration should be applied generously where there is reasonable suspicion. Substitutive administration is of particular importance, especially in the context of glucose administration and in cases of seizures associated with alcohol withdrawal delirium.</p>