Cytomegaloviruses (CMV) commonly infect man but overt disease only occurs in few patients; in the vast majority the infection is subclinical. We report on a HIV-negative pregnant woman. She suffered from a life-threatening ulcerating colitis due to CMV infection for which laparotomy was indicated. The case history is presented and suggestions are given for the surgical treatment of gastrointestinal complications such as haemorrhage, toxic colitis and perforation. Although CMV disease usually occurs in immunocompromised patients such as AIDS patients and transplant recipients, one should always keep the possibility of CMV infection in mind. The gastrointestinal tract is one of the sites of infection where the colon and terminal ileum are most frequently involved in complications such as bleeding and perforation. Gastrointestinal complications of CMV infection, although rare, can be life threatening and often require extensive surgery.