The mortality of acute kidney injury (AKI) remains unacceptably high, especially associated with acute respiratory failure. Lung injury complicated with AKI was previously considered as “uremic lung”, which is characterized by volume overload and increased vascular permeability. New experimental data using rodent models of renal ischemia–reperfusion and bilateral nephrectomy have emerged recently focusing on kidney–lung crosstalk in AKI, and have highlighted the pathophysiological significance of increased cytokine concentration, enhanced inflammatory responses, and neutrophil activation. In this review, we outline the history of uremic lung and acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), the epidemiological data on the synergistic effect of AKI and lung injury on mortality, and recent basic research which has identified possible pathways in AKI-induced lung injury. These findings will enable us to develop new therapeutic strategies against lung injury associated with AKI and improve the outcomes of critically ill patients in intensive care units.