Aims: Identificating some clinical and subclinical characteristics of ALI/ARDS among severe bum patients. Objective and Methods: A prospective study was conducted on 160 adult bum patients with bum surface area or = 20 percent, admitted to bum ICU during the first 48h post bum. ALI/ARDS was defined as the American - European Consensus Conference in 1994. Result: ARDS was recorded in 35,63 percent and ALl was 20,63 percent. As compared to ALl patients, total bum surface area (TBSA) was sgnificant higher among ARDS group (68,68 +/- 17,57 percent vs. 49,39 +/- 14,41 percent) and full thickness bum (FTB) was also higher in ARDS patients (41,25 +/- 19,82 percent vs. 22,73 +/- 15,75 percent). Foil/owing clinical and paraclinical characteristics in ALI/ARDS burn patients were recorded: Respiratory failure and severe hypoxemia with mean value of PaO2 at the diagnosed ARDS was 54.28 +/- 8.29 mmHg, PaCO2 of 44.96 +/- 8. 99mmHg, PaO:/FiO2 ratio of 118.45 +/- 25.34 in ARDS burn patients and PaO2 of 57.24 +/- 11.52mmHg, PaCO2 of 34.18 +/- 4.99mmHg, PaO/FiO2 ratio of 237.36 +/- 25.39 in ALl burn patients. Mortality rate was 80.78 percent in ARDS patients and 15.15 percent in ALl patients and extremely high among patients with inhalation injury (92.50 percent). Conclusion: ALI/ARDS was the common complication in severe burn patients. The characteristics of ALI/ARDS: Rrespiratory failure and disturbance arterial blood gas. The mortality rate of ARDS was 80. 78 percent and ALl was 15.15 percent.