Classical swine fever (CSF) is considered to be endemic in Peru with outbreaks reported to the World Organization for Animal Health as recently as 2008 and 2009. Nevertheless, little is known regarding the genetic subgroup(s) of CSF virus that are circulating in Peru or their relationship to recent CSF viruses that have been isolated from neighbouring South American countries or other parts of the world. In this study, we molecularly characterize CSF viruses that were isolated from domestic pigs from different regions of Peru from the middle of 2007 to early 2008. All virus isolates were found to belong to genetic subgroup 1.1, consistent with the subgroup of viruses that have been identified from other South American countries. Although the Peruvian isolates are most closely related to viruses from Colombia and Brazil, they form a monophyletic clade, which suggests they have a distinct evolutionary history. ©2010 Canadian Food Inspection Agency.