The consequences of neonatal herpes simplex virus (HSV) infection can be severe. Disease can be localized to skin, eye and mouth (SEM disease), involve the central nervous system (CNS) or manifest as disseminated infection involving multiple organs. Most surviving infants in the latter two categories have neurological sequelae, and the mortality rate in the absence of therapy is very high (80%) for babies in the latter category. The International Herpes Management Forum (IHMF) has produced guidelines on the diagnosis, prevention and effective management of neonatal herpes. Neonatal herpes may occur in the absence of skin lesions, so if the infection is suspected, swabs of the oropharynx, conjunctiva, rectum, skin lesions, mucosal lesions and urine should be promptly taken and submitted for virus culture. Cerebrospinal fluid (CSF) should be submitted for polymerase chain reaction (PCR) detection of HSV DNA. Evidence for disseminated or CNS infection should be sought using liver function tests, complete blood cell count, CSF analysis and chest X-ray, if respiratory abnormalities are present. Neonates with suspected HSV infection should be treated with intravenous aciclovir (20 mg/kg) every 8 h for 21 days. If disease is localized to the SEM, treatment should be limited to 14 days. The neutrophil count for children receiving intravenous aciclovir should be monitored. If the absolute neutrophil count falls below 500/mm3, decreasing the aciclovir dose or administering granulocyte colony stimulating factor (GCSF) should be considered. At the end of therapy in CNS and disseminated disease, PCR assessment of CSF should be used and treatment continued if the child remains PCR positive at this site.