Here, we report the genome sequence of a spider monkey alphaherpesvirus (ateline alphaherpesvirus 1, HVA1) and compare it with that of other primate alphaherpesviruses. The HVA1 genome is 147,346 bp long and contains 67 predicted ORFs. The genetic layout of the HVA1 genome is similar to that of the squirrel monkey alphaherpesvirus (saimirine alphaherpesvirus 1, HVS1) in that it lacks inverted repeat regions flanking the unique long region and homologues of the UL43, UL49.5, US8.5 and US10-12 genes. Unlike HVS1, HVA1 also lacks a homologue of the RL1 (γ34.5) gene and a replication origin near the end of the genome. Consistent with previous phylogenetic analyses, all predicted proteins of HVA1 are most closely related to those of HVS1.