INTRODUCTION: In clinical reports on coronavirus disease 2019 (COVID-19), the incidence of acute kidney injury (AKI) is extremely variable, although AKI is described as an independent risk factor for mortality. A meta-analysis was performed to clarify the incidence and the impact of COVID-19-related AKI on mortality. METHODS: All trials reporting the incidence of AKI in COVID-19 patients were searched using MEDLINE, the Cochrane Library, and EMBASE databases (last update April 26, 2020). RESULTS: Ten trials with a sample of 5,166 patients were included. AKI occurred in 947 out of 5,166 (18.3%) patients. AKI incidence was higher in severe cases: 62/305 severe patients developed AKI (20%) versus 27/1,268 nonsevere patients (2%) (p = 0.00001). AKI occurred in 475 out of 915 (52%) deceased patients versus 183 out of 2,678 (7%) survivors (p = 0.00001). Continuous renal replacement therapy was significantly more frequent in severe cases and in dead patients. CONCLUSION: A significant increase in mortality rate was observed in COVID patients who developed AKI, and AKI incidence was also higher in severe cases. Any supportive strategies to protect kidney could represent valuable intervention to reduce mortality in severe COVID-19 patients.