An infection by HHV-7 with presence of virus DNA in the spinal fluid was ascertained in a twenty five month old boy with an epileptic syndrome shortly after birth. The child was frequently admitted to hospital due to his basal disease and frequent bacterial infections. In the occasion of one of these hospital admissions for bacterial infections in conjunctiva, spleen and a lung, virological investigations were also carried out disclosing the presence of HHV-7 DNA in a sample of spinal fluid and of serum and the absence of DNAs from the other herpesviruses. The patient's monitoring for HHV-7 showed the presence of HHV-7 DNA in a sample of serum and in various samples of peripheral blood lymphocytes and saliva, but not in the cerebrospinal fluid sample successive to that positive for HHV-7 DNA. Forty seven days before the diagnosis of HHV-7 infection, the patient received a human gamma-globulin therapy which obscured the humoral response mounted against the virus by the host, so, whether the HHV-7 presence in the central nervous system was associated with a primary or a reactivated infection remained uncertain. The absence of detectable HHV-7 serum IgM antibody, however, suggests the HHV-7 DNA finding on the occasion of a virus reactivation rather than a primary infection. The virological data suggest that HHV-7 may have possibly reached the central nervous system in the course of a viremia. The absence of HHV-6 and HHV-7 antibodies, present in the patient's serum at a high level, support the integrity of the blood-brain barrier. A possible pathogenetic role of HHV-7 in the child's disease seems unlikely, since the epileptic syndrome was pre-existing.