Purpose Comorbidity has a significant impact on the health status and treatment outcome of a patient. The Charlson comorbidity index (CCI) is a frequently used scoring system, which evaluates the prognosis based on the patient's comorbid conditions. The aim of this study was to evaluate the usefulness of CCI in predicting the mortality and renal recovery in non-critically ill patients with severe AKI. Methods A total of 530 adult patients who were referred from the emergency department and underwent intermittent urgent hemodialysis (uHD) were enrolled in the study. Personal history for comorbidities were recorded and then assessed using the CCI. Results The mean CCI score was 3.3 +/- 2.6. In our multivariate analysis, higher white blood cell count was associated with mortality (p = 0.023). The other parameters including CCI score were not found to be significantly associated with mortality excluding patients with sepsis. Moreover, the CCI was not significantly useful in the discrimination of patients with complete recovery from patients who remained dependent to dialysis. Conclusions We could not find significant association between CCI and short-term hospital mortality and renal outcome. Whereas, malnutrition, inflammation and general aging may have impact on short-term mortality among patients.