Introduction: Acute respiratory distress syndrome places a significant burden on the health-caresystem, with an estimated prevalence of 7% of ICU admissions and an unacceptable hospitalmortality rate of 50%. Pulmonary and systemic inflammation are the pathophysiologic hallmarksof this syndrome, and activation of the glucocorticoid receptor in pulmonary and circulating cellsis an essential step in restoring homeostasis. While changing the ventilator settings to low tidalvolume reduces systemic inflammation with a favorable impact on survival, a concomitant antiinflammatorypharmacologic intervention should lead to a more rapid resolution of ARDS andearlier extubation. Methods: Our study was conducted on thirty patients admitted in the CriticalCare Department, Cairo University Hospital with proven diagnosis of Early Severe ARDS. Thestudied population was divided into two groups: Group I: Twenty patients were subjected tomethylprednisolone treatment protocol plus conventional management for ARDS and Group II:Ten patients were kept on conventional management for ARDS. All the studied population weresubjected to full history taking, detailed clinical examination, full laboratory investigations, pancultures,APACHE II scoring system, MODS score on days(1 and 7),LIS on days (1,2,3,5and 7),serial chest radiographs ,invasive arterial line insertion, pulmonary artery catheter insertion,serial measurements of CRP on days (1,3,5 and 7) ,testing of adrenal function, lung protectivestrategy protocol and evaluation of the outcome as regards 1-point reduction in LIS orsuccessful extubation ,duration of MV, length of ICU stay and ICU mortality.Results: In our study , there were significantly lower values of MODS score on day (7) ingroup I compared to group II patients (1.8+1.1 vs 2.7+0.9 respectively, P value: 0.022),also wefound that there was statistically significant decline in LIS in day (7) in group I compared togroup II patients (1.925+0.815 vs 2.85+0.5676 respectively ,P value: 0.003) and a significantlower CRP values on day 7 in group I compared to group II patients was found(8.35+7.741mg/dL vs22.1 +16.394 mg /dL, p value:0.004) respectively. By day 7: The responseof the two groups clearly diverged; the methylprednisolone-treated group had a statisticallysignificant difference as regards a)1-point reduction in LIS (70% of patients in group I vs 20%of patients in group II , P value: 0.028) and b) successfully extubation(11 patients in group I vs 1patient in group II,P value: 0.048), moreover the treated patients had a statistically significantdecrease in number of days of MV of (11.15 + 7.08 in group I vs 20.9+9.08 in group IIrespectively, P value 0.004). Our study did not demonstrate any significant difference in theincidence of new infection, neuromuscular weakness, uncontrolled hyperglycemia and GITbleeding complications between the treatment and control groups,( p values: 0.7945,0.954 ,0.446 and 0.954) respectively. Also no significant difference in the length of ICU stay and ICUsurvival between group I and group II patients was found (P value: 0.846 and 0.06) respectively.Conclusions: The use of low-dose corticosteroids provides evidence of efficacy in EARLYSEVERE ARDS (accelerated resolution of systemic and pulmonary manifestations of ARDSwith significant reduction in duration of mechanical ventilation) with less adverse effect