Acute kidney injury (AKI) is common and associated with increased risks of cardiovascular and chronic kidney disease. Causative molecular/physiological pathways are poorly defined. There are no therapies to improve long-term outcomes. An activated endothelin system promotes cardiovascular and kidney disease progression. We hypothesized a causal role for this in the transition of AKI to chronic disease. Plasma endothelin-1 was threefold higher; urine endothelin-1 was twofold higher; and kidney preproendothelin-1, endothelin-A, and endothelin-B receptor message up-regulated in patients with AKI. To show causality, AKI was induced in mice by prolonged ischemia with a 4-week follow-up. Ischemic injury resulted in hypertension, endothelium-dependent and endothelium-independent macrovascular and microvascular dysfunction, and an increase in circulating inflammatory Ly6Chigh monocytes. In the kidney, we observed fibrosis, microvascular rarefaction, and inflammation. Administration of endothelin-A antagonist, but not dual endothelin-A/B antagonist, normalized blood pressure, improved macrovascular and microvascular function, and prevented the transition of AKI to CKD. Endothelin-A blockade reduced circulating and renal proinflammatory Ly6Chigh monocytes and B cells, and promoted recruitment of anti-inflammatory Ly6Clow monocytes to the kidney. Blood pressure reduction alone provided no benefits; blood pressure reduction alongside blockade of the endothelin system was as effective as endothelin-A antagonism in mitigating the long-term sequelae of AKI in mice. Our studies suggest up-regulation of the endothelin system in patients with AKI and show in mice that existing drugs that block the endothelin system, particularly those coupling vascular support and anti-inflammatory action, can prevent the transition of AKI to chronic kidney and cardiovascular disease.