The objectives of the study were to assess organ dysfunction in burn patients by using the Sequential Organ Failure Assessment (SOFA) score, to determine the relationship between early (day 1) and late (day 4) organ dysfunction, as well as the change in organ dysfunction from admission to day 4, and mortality. The design was a prospective observational cohort study. Patients were admitted to our intensive care burn unit with severe thermal burns (> or =20% total body surface area [BSA] burned) or inhalation injury with a delay from injury to admission less than 12 h and a length of stay less than 3 days (n = 439; age, 46.0 +/- 20.3 yrs; total BSA burned, 31.6% +/- 20.2% [mean +/- SD]; inhalation injury, 44.4%; crude mortality, 18.5%). Sequential Organ Failure Assessment scores were measured on admission (SOFA 0) and on subsequent days (SOFA 1, SOFA 2, SOFA 3, and SOFA 4). The difference between SOFA 0 and SOFA 4 (DeltaSOFA 0-4) was calculated. Multivariate logistic regression analyses, including other variables associated with mortality in the models, were performed to calculate adjusted odds ratios (ORs) of organ dysfunction measurements for mortality. After adjusting for age, BSA burned, diagnosis of inhalation injury, and sex, SOFA 1 (OR, 1.89; 95% confidence interval [CI], 1.55-2.32), SOFA 4 (OR, 1.33; 95% CI, 1.19-1.47), and DeltaSOFA 0-4 (OR, 1.40; 95% CI, 1.28-1.55) were independently associated with mortality. The SOFA score is useful to assess organ dysfunction in burn patients. Burn-induced organ dysfunction (early and late), as well as the change in organ dysfunction, is independently associated with mortality.