Objective: Old age is a risk factor for Clostridioides difficile infection (CDI). As the world’s aging population increases, identifying risk factors for CDI in elderly patients is a matter of urgency. This study examined the relationship between CDI relapse and nutritional status using the geriatric nutritional risk index (GNRI).Patients and Methods: Between January 2016 and December 2021, 108 patients were diagnosed with CDI. Of the 108 patients, 19 were excluded because of younger age (<65 years), early death within 14 days of the initial CDI diagnosis, and insufficient data. The patients were divided into low- (<75) and high-GNRI groups (≥75) based on the receiver operating characteristic curve analysis. Variables associated with CDI relapse were also analyzed.Results: The median GNRI scores in all patients and in the low- and high-GNRI groups were 74.9, 68.9, and 83.9, respectively. Of the 89 patients, 28 (31.8%) experienced a CDI relapse. The log-rank test showed a significantly better relapse-free survival (RFS) in the high GNRI group (P=0.002). Univariate analysis revealed that low GNRI (P=0.004), chronic kidney disease (CKD) (P=0.004), and beta-lactamase inhibitor administration before the initial diagnosis of CDI (P=0.025) were significantly correlated with RFS. Multivariate analysis revealed that low GNRI (P=0.008) and CKD (P=0.010) were independent prognostic factors for RFS.Conclusion: Among elderly patients, a low GNRI was strongly associated with CDI relapse. Our study may help clinicians to consider therapeutic strategies for elderly patients with CDI.