Pulmonary diseases including acute respiratory distress syndrome (ARDS), idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD) affect millions of individuals, and are associated mostly with high mortality and even death. To date, there is no therapeutic option available to stop the progression of pulmonary diseases, making it a major scientific challenge and public health concern. Although the molecular and cellular mechanisms involved in lung pathogenesis are not fully elucidated, a wealth of evidence indicates that reactive oxygen species generated by NOX enzymes might be major actors in lung pathogenic processes. Indeed, NOX enzymes are expressed in different human and rodent lung cell types and contribute to the development of lung diseases in a broad range of animal models. In this context, targeting NOX enzymes might represent a novel strategy for a cure of lung diseases. In the current thesis, the knowledge relating to the cellular expression and the function of NOX enzymes in physiological and pathological situation will be summarized. In addition, the potential place of NOX inhibitors for the treatment of lung diseases will be addressed.