Acute respiratory distress syndrome (ARDS) is a common critical disease in clinic, which refers to acute hypoxic respiratory failure caused by various insults, with bilateral fluffy infiltrates on chest radiography. It is reported that gender may play a critical role in the occurrence, severity, and outcomes of ARDS. Nevertheless, gender difference in ARDS is still controversial because of the complexity of the disease. This paper summarized the sex difference in epidemiology of ARDS according to different etiologies such as sepsis, trauma and respiratory viruses, and discussed gender-bias in the occurrence, severity and outcomes of ARDS. Moreover, we clarified briefly the mechanism that may contribute to the gender-bias to provide novel ideas for clinical treatment of ARDS.