['To examine clinical outcomes in hospitalized Clostridium difficile infection (CDI) patients with acute kidney injury (AKI) using the National Hospital Discharge Survey for 2005 to 2009.', 'CDI can cause serious complications in hospitalized adults. On the basis of expert opinion, guidelines recommend AKI as a marker of severe CDI, but this has not been extensively validated.', 'CDI and AKI patients were identified using International Classification of Diseases 9th edition codes. Weighted data analyses were performed to provide national estimates and compare outcomes in patients with AKI and CDI to CDI patients without AKI.', 'There were an estimated 1,261,712 patients with CDI identified with a median age of 75 years; 59.2% were female and 17.5% developed AKI. On multiple variable analysis, after adjusting for age, sex, and comorbid conditions, AKI was independently associated with length of hospital stay increase by 1.9 days, risk of colectomy with an odds ratio (OR) of 1.35, all-cause in-hospital mortality (OR, 2.76), and dismissal to a care facility (OR, 1.43), all P<0.0001.'] Is acute kidney injury an independent marker of severity in Clostridium difficile infection : a nationwide survey?