The study retrospectively analyzed 118 patients (mean age 41 years, 52.5% male) with acute fulminant myocarditis (AFM) and acute kidney injury (AKI) at Fuwai Huazhong Hospital from March 2018 to September 2020. Patients were divided into death (n=44) and survival (n=74); the death group had higher rates of respiratory failure, use of extracorporeal oxygenation, mechanical ventilation, and continuous renal replacement therapy. The death group had significantly higher levels of proteinuria, leukocytes, neutrophils, neutrophil-to-lymphocyte ratio (NLR), systemic inflammatory response index (SIRI), troponin, creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and serum creatinine, while 24-hour urine volume, ejection fraction (EF), and length of hospitalization were lower (p<0.05). The number of leukocytes, neutrophils, NLR and SIRI were positively correlated with 30-day mortality. Multivariate logistic regression identified 24-hour urine volume (OR 0.999, 95% CI 0.999–1.000, p=0.036) and EF (OR 0.944, 95% CI 0.896–0.995, p=0.032) as independent predictors of 30-day mortality. ROC curve analysis showed a predictive value with an AUC of 0.819 for urine volume and 0.740 for EF. SIRI was associated with 30-day mortality, but only reduced 24-hour urine volume and EF were independent prognostic markers.