Clinical predictors of in-hospital fatality were assessed in 191 persons admitted to the Yale-New Haven Hospital Intensive Care Unit with a diagnosis of congestive heart failure. In the 17 (8.9%) patients who died, the most important individual predictors among the presenting clinical features were absence of dyspnea, presence of anterior chest pain or jugulovenous distension, and cardiac severity due to ischemia, valvular disease, or arrhythmia. Two important predictors, largely neglected in previous literature, were a prior history of congestive heart failure and a poor clinical response after 24 h of therapy. Multivariable analysis led to the identification of 6 features (age greater than 70 y, prior history of congestive heart failure, jugulovenous distension, chest pain, cardiac severity, and poor early response to therapy) that could be combined into a simple clinical predictive index. The new index identified 5 prognostic groups with fatality rates of 0, 3.5, 7.4, 19.2, and 85.7 percent. An advantage of the clinical index is the identification of a subgroup of patients, with low risk for fatality, who may not need prolonged treatment in an intensive care unit.