Objective: To study the spectrum and outcome of severe scrub typhus in adult patients and to predict the hospital mortality by organ failure on admission. Methods: This was a prospective observational cohort study conducted between July 2017 and October 2020 at the medical emergency centre of PGIMER, Chandigarh, India. One hundred and twenty-six patients aged =13 years were diagnosed with scrub typhus. Severe disease was defined as the presence of organ failure based on the Sequential Organ Failure Assessment (SOFA) score on admission. Results: About two-thirds of the patients were from geographic regions outside the endemic sub-Himalayan belt. Fever (99.21%) and dyspnea (79.36%) were the most frequent complaints. Respiratory failure (81.75%) was the most common organ failure, followed by hepatic (52.38%), coagulative (47.62%), circulatory (33.33%), renal (21.43%), and cerebral dysfunction (13.49%). The median (Q1, Q3) SOFA score was 8 (6, 9), and 48.41% of the patients had a quick-SOFA score =2. Organ supports with invasive ventilation (40.48%), vasopressors (36.51%), and renal replacement therapy (7.14%) were frequently required. The in-hospital mortality was 11.90% and was independently predicted by circulatory and hepatic failures on multivariate logistic regression (OR 11.12, 95% CI 1.73-71.31 and OR 8.49, 95% CI 1.18-61.41, respectively). Conclusions: Most patients had pulmonary dysfunction; circulatory or hepatic failure on admission strongly predicts death.