A 71-year-old woman developed a small bowel perforation due to cytomegalovirus infection. She did not taken any immunosuppressive medication and her cellular immunity was normal. Surgical resection and antiviral therapy with ganciclovir led to complete recovery. As far as we know, this paper reports the first case of small bowel perforation due to cytomegalovirus infection in a non-immunocompromised patient. Nevertheless the patient was known with diabetes mellitus. It should be emphasised that elderly patients have impaired immune defences and may be unsuspected hosts of opportunistic infections.