Two hospital outbreaks of Clostridium difficile diarrhoea in two general surgery units of different hospitals are described. Moreover, the results of a study on the circulation of C. difficile in a neurosurgery unit following two cases of colitis are reported. C. difficile strains isolated from patients and environment have been typed using antimicrobial susceptibility testing and electrophoretic profiles of EDTA-extracted proteins. The majority of strains isolated in each hospital shared the same protein profile and the same pattern of antibiotic susceptibility. This provides strong evidence of cross-infection and hospital acquisition of C. difficile.