Low-to-moderate doses of corticosteroids have been reported to improve outcome in severe community acquired pneumonia. In the present study, it was speculated whether the administration of low doses of glucocorticoids to patients with severe ventilator-associated pneumonia (VAP) would improve outcome in terms of increased survival and enhanced weaning from ventilator/ support, and reduction of the severity of system organ dysfunction. Methods: Forty-nine patients diagnosed clinically and bacteriologically as having VAP were studied, 34 of whom had system organ dysfunction and were randomized to receive hydrocortisone infusion in daily doses of 240 mg for 7 days (n=17) or no hydrocortisone (n=17), besides the antimicrobial therapy. Kaplan-Meier curves for survival and weaning from mechanical ventilation at 14 and 28 days from randomization were constructed and compared with the log-rank test. System organ dysfunction was quantified at 3, 7, 14, and 28 days using relevant scoring systems. Results: By day 14, 14 {82.4%} patients in the hydrocortisone group had been off the ventilator compared with 4 {23.5%} patients in the control group (P 0.05). By day 28, 15 {88.2%} patients in the hydrocortisone group had been off the ventilator compared with 7 {41.2%} patients in the control group (P } patient in the hydrocortisone group had died compared with 6 {35.3%} patients in the control group (P