Background <p>Tetanus is a life-threatening but vaccine-preventable disease. Despite existing preventive measures, severe tetanus continues to impose a significant burden in low- and middle-income countries. However, contemporary data on the clinical characteristics, treatment strategies, complications, and prognosis of patients with severe tetanus remain limited.</p> Methods <p>We conducted a retrospective observational cohort study of adult patients with severe tetanus (Ablett grade III or IV) admitted to the intensive care unit (ICU) of a tertiary infectious disease hospital from January 2014 to December 2024. Patient demographics, clinical manifestations, laboratory findings, treatment strategies, complications, and outcomes were extracted from electronic medical records and summarized using descriptive statistical methods.</p> Results <p>A total of 36 patients were included, the majority were older men from rural areas, and relatively few had received post-exposure prophylaxis. In the early stage of the disease, dysphagia and generalized muscle hypertonia were more frequent than classic symptoms such as trismus and opisthotonos. Most patients required tracheostomy, deep sedation, neuromuscular blockade, and invasive mechanical ventilation. Infectious complications were common, particularly pulmonary infections (80.6%). More than half of the patients (55.6%) had culture results indicating antimicrobial resistance. The median ICU length of stay was 27.5 days, and the in-hospital mortality rate was 16.7%.</p> Conclusion <p>Although severe tetanus is potentially fatal, outcomes can be improved with advanced intensive care management. Early intervention, comprehensive supportive therapy, strict infection control, and strengthened tetanus vaccination and post-exposure prophylaxis strategies are crucial.</p>