The independent risk factors to predict mortality of critical severe acute respiratory syndrome (SARS) were investigated. One hundred and two patients diagnosed with critical SARS were admitted to hospitals of Shanxi Province, from March 7, 2003 to June 4, 2003. The patients were prospectively studied after admission to access their short term outcomes and the risk factors associated with adverse outcomes, defined as death. All the demographic and clinical characteristics were studied and univariate and multivariate Logistic regression were employed to access the risk factors.The results showed that of the 102 cases, 23 patients died, with a crude mortality rate of 22.5%.Multivariate Logistic regression revealed that age above 50 [odds ratio (OR) 1.10, 95 % confidence internal (CI) 1.03 to 1. 16, P=0. 004], lymphopenia at early stage (OR 14.62, 95 % CI 1.78 to 11.97, P= 0.01) were independently associated with mortality. On the other side, psychotherapy (OR 0.01, 95 % CI 0.00 to 0.06, P＜0.001) was independently associated with aliveness. It was concluded that critical SARS is a new disease entity that carries significant mortality and morbidity. Specific clinical and laboratory parameters predicting unfavorable and favorable outcomes have been identified.