The complete DNA sequence of equine herpesvirus 2 (EHV-2) strain 86/67 was determined, The genome is 184,427 bp in size and has a base composition of 57.5% G + C. Unusually for a herpesvirus, about a third of the sequence distributed in several large blocks appears not to encode proteins. The 79 open reading frames that were identified as probably polypeptide-coding are predicted to encode 77 distinct proteins. Amino acid sequence comparisons confirmed that EHV-2 is a γ-herpesvirus that is genetically collinear with herpesvirus saimiri (HVS; a γ2-herpesvirus) and Epstein-Barr virus (EBV; a γ1-herpesvirus), with a closer relationship to the former. Moreover, EHV-2 specifies eight proteins that have counterparts in HVS but not in EBV and only a single protein that has a homologue in EBV but not in HVS (EBV BCRF1, which encodes and interleukin 10-like protein). EHV-2 also encodes three potential G protein-coupled receptors, one with a counterpart in HVS that is specific for α chemokines, another with a counterpart in human cytomegalovirus (a β-herpesvirus), which is specific for β chemokines, and a third that is assigned more tentatively and lacks detectable counterparts in other herpesviruses.