Patients critically ill from abdominal diseases under controlled ventilation showed statistically significant differences in some vital signs and measurements immediately after admission to the intensive care unit, when grouped according to survivors (34 patients) and nonsurvivors (40 patients). On the basis of a stepwise linear discriminant analysis a practicable method of prognosis from data of the first 24 hours could be achieved, which enables a correct prediction of outcome in 91% of the survivors and 79% of the nonsurvivors.