Currently a rarity in high-income countries, tetanus is a diagnosis not to miss. Deaths from tetanus fell by almost 90% between 1990 and 2019, largely reflecting the success of WHO’s Maternal and Neonatal Tetanus Elimination campaign. However, deaths among children and adults have plateaued, and tetanus remains an important vaccine-preventable cause of morbidity and mortality, notably in southern Asia, southeast Asia, and sub-Saharan Africa. Tetanus results from infections with spore-forming Clostridium tetani bacteria, usually acquired via contaminated wounds and burns. C tetani releases a potent neurotoxin, causing muscle spasms, rigidity, and dysautonomia. Important complications include laryngeal spasm and resultant airway obstruction and respiratory arrest, nosocomial infections, and sequelae of prolonged immobility. Tetanus is usually diagnosed on the basis of clinical signs and symptoms, but microbiological tests can serve as useful adjuncts. Treatment is multifaceted, requiring source control, antibiotic therapy, and antitoxin administration. With prolonged, quality intensive care, many patients survive with good functional outcome. However, due to challenges in leveraging routinely-collected health-care data and performing high-quality trials in resource-constrained settings, several key questions remain unanswered and optimal treatment strategies are contested. In this Review, we provide a state-of-the-art summary of global tetanus epidemiology, its clinical features and differential diagnosis, principles of management, and prognosis.