Acute Respiratory Distress Syndrome (ARDS) remains a significant clinical challenge, with its pathogenesis not fully understood. Proteomic analyses of plasma and bronchoalveolar lavage fluid (BALF) in patients with ARDS have been performed to uncover diagnostic and prognostic markers, although previous studies have not adequately focused on longitudinal biomarker comparison. This study aims to elucidate the proteomic profiles of patients with ARDS in acute and subacute phases to better understand pathophysiological progression of ARDS.