From November 1, 1982 through December 31, 1985, there were 19 centers and 382 patients that evaluated the effect of methylprednisolone sodium succinate (MPSS) on the septic syndrome. Seventeen of these centers enrolled 304 patients in a prospective, randomized, double-blind, placebo-controlled study to determine if early treatment with MPSS would decrease the incidence of severity of the adult respiratory distress syndrome (ARDS) in patients at risk of ARDS from sepsis. To ensure early institution of the MPSS or placebo therapy (PLA), patients with the presumptive diagnosis of sepsis were identified. That diagnosis was based on the presence of fever or hypothermia (temperature greater than 38.3 degrees C or less than 35.5 degrees C, rectal), tachypnea (greater than 20 bpm), tachycardia (greater than 90 bpm) and the presence of one of the following indices of organ dysfunction: a change in mental status, hypoxemia, elevated lactate levels or oliguria. The treatment, either MPSS 30 mg/kg or PLA, was given in four 20-minute infusions six hours apart and was initiated within two hours of the presumptive diagnosis of sepsis. The development and reversal of the adult respiratory distress syndrome (ARDS) was followed and resulted in data on 304 of the 382 randomized patients. A trend toward increased incidence of ARDS was seen in the MPSS group 50/152 (32 percent) compared to the placebo group 38/152(25 percent) p = 0.10. Significantly fewer MPSS patients reversed their ARDS 15/50 (31 percent) compared to placebo 23/38 (61 percent) p = 0.005. The 14-day mortality in patients with ARDS treated with MPSS was 26/50 (52 percent) compared to placebo 8/22 (22 percent) p = 0.004. We conclude that early treatment of septic syndrome with MPSS does not prevent the development of ARDS. Additionally, MPSS treatment impedes the reversal of ARDS and increases the mortality rate in patients with ARDS.