Seventeen critically ill patients were studied prospectively to determine the relationship of serum albumin, creatinine-height index (CHI) and weight-height index (WHI) to clinical outcome. Use of the conventional "normal values" as cut-offs failed to discriminate between survivors and nonsurvivors better than chance alone. A serum albumin less than 2.5 g/dl correctly separated 93% of the patients in terms of survival prognosis.