Data reported recently suggest that acute kidney injury (AKI) is a systemic disease that adversely affects the function of other organs.including the heart, lung, liver, brain and immune system.which is related to the high mortality rate of affected patients. Kidney and lung function are closely related in both health and disease. Data support deleterious bidirectional crosstalk between the lung and kidney. AKI is a common complication in patients with acute respiratory distress syndrome, and has been reported to exert adverse effects on the lungs. Mortality rates for AKI combined with acute lung injury (ALI) can be up to 80% in critically ill patients. Although AKI-associated ALI presents clinically as increased pulmonary edema, the mechanism of AKI-associated ALI extends beyond simple volume overload. Data from animal studies suggest that AKI-induced pulmonary edema is related to both cardiogenic edema (due to elevated hydrostatic pressure) and non-cardiogenic edema (due to pulmonary endothelial and epithelial cell injury caused by inflammation, oxidative stress, and apoptosis). ALI with mechanical ventilation causes a decline in renal hemodynamic function and apoptosis. Elucidation of the mechanisms of kidney.lung crosstalk would facilitate development of effective therapies and reduce the mortality rate of AKI combined with respiratory failure. (Korean J Med 2016;90:389-393)