Clostridium difficile is a major cause of chronic antibiotic-associated diarrhea and a significant health care-associated pathogen that forms highly resistant and infectious spores. Spo0A is a highly conserved transcriptional regulator that plays a key role in initiating sporulation in Bacillus and Clostridium species. Here, we use a murine model to study the role of the C. difficile spo0A gene during infection and transmission. We demonstrate that C. difficile spo0A mutant derivatives can cause intestinal disease but are unable to persist within and effectively transmit between mice. Thus, the C. difficile Spo0A protein plays a key role in persistent infection, including recurrence and host-to-host transmission in mice.