Equine herpesvirus (EHV) 1 is an important pathogen of horses. Upon infection, the virus replicates in theupper respiratory tract. Then it spreads to internal organs via a cell-associated viremia. Local replication in in -ternal o gans may result in abortion and nervous system disorders. The currently designed vaccines are not ableto induce significant protection against EHV1-induced viremia. However, several vaccines are able to induce asignificant level of protection against either abortion or nervous system disorders. Which immune responsescorrelate with this protection is so far unknown. Besides vaccination, management will remain a crucial factor inthe prevention of EHV1-induced clinical signs. Management measures include the vaccination of all horses onthe premises to reduce infection pressure; the separate housing of young horses, adult horses and pregnant mares;strict hygiene measures and strict control of contact with horses from outside the premises. If, despite vaccination andthorough management, an outbreak of EHV1-induced disease occurs, treatment with antiviral agents may be useful.