Background Antimicrobial Stewardship Programs (ASP) aim to ensure the appropriate use of antibiotics. There is limited literature evaluating ASP outcomes in hospitalized geriatric patients who are at higher risk for developing Clostridium difficile infection (CDI) or other adverse outcomes. The primary objective of this study was to determine if ASP efforts in this age group decreases the rate of 30-day hospital readmissions due to reinfection or development of CDI, hospital length of stay (LOS) and mortality. Methods A retrospective chart review was performed to compare the rates of 30-day hospital readmissions because of reinfection or development of CDI in patients 65 years and older who received ASP interventions between January and June 2017. A control group of patients 65 years and older who received antibiotics between January and June 2015 (pre-ASP) was analyzed for comparison. We also assessed their mortality rate and LOS. Patients were included if they received antibiotics for pneumonia (PNA), urinary tract infection (UTI), acute bacterial skin and skin structure infection (ABSSSI) and complicated intra-abdominal infection (cIAI). The ASP team consisted of an infectious diseases physician and a clinical pharmacist who met daily to review patients on broad spectrum antibiotics. ASP interventions consisted of de-escalation of empiric or definitive therapy, change in duration of therapy or discontinuation of therapy. Results Overall, 834 patients (540 control; 294 intervention) were included. The 30-day hospital readmission rate for all infection types decreased during the intervention period (19.6% vs 4.8%, P=0.0001). Both the development of CDI during hospital stay and 30-day readmission due to CDI during the intervention period decreased (2.6% vs 0.34%, P=0.019). There was no statistically significant decrease in 30-day hospital readmissions in the PNA (58.5% vs. 35.7%, P=0.11), UTI (18.9% vs. 35.7%, P=0.15), ABSSSI (12.3% vs. 21.4%, P=0.34) or cIAI (10.4% vs 7.1%, P=0.14) arms. There was no statically significant change in LOS (7.50 days vs 7.26 days, P=0.48) or mortality (9.6% vs 6.5%, P=0.12). Conclusion Multidisciplinary ASP efforts significantly reduced 30-day hospital readmission rates and development of CDI in hospitalized patients 65 years and older. Disclosures All Authors: No reported disclosures