Ischemic acute kidney injury (AKI) is a serious renal dysfunction caused by surgical invasion and transplantation. Proximal tubular damage is known to be the main characteristics of pathological progression in ischemic AKI. However, the involvement of distal tubule in ischemic AKI remains well unknown. We have previously shown that Na⁺/Ca²⁺exchanger type 1 (NCX1) is expressed on the basolateral side in distal convoluted tubule and is involved in urine production and electrolyte exertion. In this study, we evaluated the pathophysiological significance of distal tubular NCX1 in ischemic AKI, using distal tubular-specific NCX1 deficient (NCX1-cKO) and NCX1 transgenic (NCX1-TG) mice. We subjected these mice and wild-type mice to sham surgery or 30 min of unilateral renal ischemia and reperfusion (IR) with contralateral nephrectomy. BUN and serum creatinine were significantly increased in both NCX1-TG mice and wild-type mice after IR injury. In contrast, these increases were remarkably suppressed in NCX1-cKO mice after IR injury. The histological findings showed that the distal tubular damages after IR injury were alleviated in NCX1-cKO mice, but were exacerbated with macrophage infiltration to renal medulla in NCX1-TG mice. These results suggest that distal tubular NCX1 plays a critical role in the pathophysiology of ischemic AKI.