The performance of a hospital- and community-onset Clostridium difficile infection definition using administrative data with a present-on-admission indicator was compared with definitions using clinical surveillance. For hospital-onset C. difficile infection, there was moderate sensitivity (68%) and high specificity (93%); for community-onset, sensitivity and specificity were high (both 85%). Infect Control Hosp Epidemiol 2015;00(0): 1-3.