The beta-herpesviruses, human herpesviruses-6 and -7 (HHV-6 and HHV-7), are closely related and have very similar biological behaviour. While HHV-6 is associated with encephalitis in immunosuppressed adults, HHV-7 is not recognised as a cause of neurological disease in such patients. This report describes the identification of a reactivated HHV-7 infection in the cerebrospinal fluid of an adult who presented with an acute myelitis 11 months after unrelated donor bone marrow transplant.