This retrospective study reviews cases of ARDS (Adult Respiratory Distress Syndrome) treated and followed up from October 1988 to December 1990 in the Pediatric Intensive Care Unit of Instituto Fernandes Figueira/FIOCRUZ, Brazil. Clinical, radiological and histopathological features were analyzed and correlated with well defined stages of the disease process. Out of 459 cases, 49 (11%) were selected for further study. In 11 cases, histopathological examination (4 biopsies and 8 autopsies) was performed and then classified into one of the following phases: exsudative, cellular proliferative and late fibrotic. The work emphasizes the need for further clinical and experimental studies in order to define the mechanisms and the impact of this Syndrome in the pediatric population.