Clostridium difficile is primarily recognised as a nosocomially acquired pathogen manifesting in gastrointestinal disease subsequent to the patient receiving broad-spectrum antibiotics. Infection can be sporadic, but outbreaks commonly occur within a ward or hospital as a result of cross-infection. Since the 1980s, the epidemiology of C. difficile disease has been studied by the application of many different typing or fingerprinting methods; these, and the lessons learned, are reviewed herein.