Acute kidney injury (AKI) is an important feature of thrombotic microangiopathy (TMA). This present study aimed to describe and analyze the characterization, prevalence, and prognosis in TMA patients with AKI. This study was an observational, retrospective patient cohort study in which patients were classified as AKI and non-AKI groups. An analysis of the relationship between the risk factors and AKI and in-hospital mortality was conducted using logistic regression. Kaplan-Meier curves were adopted to obtain the link between AKI and in-hospital mortality. There were 27 and 51 patients in the AKI and non-AKI groups, respectively, and the morbidity and mortality of AKI were 34.62% and 40.74%, respectively. AKI was associated with an older age (P = .033) and higher infection rates (P < .001). In comparison with the non-AKI group, the AKI group had tremendously intrarenal manifestations: hematuria (P < .001), proteinuria (P < .001). The AKI group received all continuous renal replacement therapy treatment (P < .001), but fewer glucocorticoids were used (P = .045). In-hospital mortality (P = .045) were higher in the AKI group. The risk factors for AKI (P = .037) were age. In addition, higher total bilirubin (P = .011) and age (P = .022) were significantly correlated with increasing risk of in-hospital mortality. Survival analysis by Kaplan-Meier revealed a significantly poor prognosis predicted by the AKI group (P = .045). Acute kidney injury could be commonly seen in TMA pneumonia and was related to a higher mortality rate.