Although traditionally considered a disease of dairy cattle, in some parts of the US, Bovine Leukemia Virus (BLV) infection is quite prevalent in beef cattle as well. Bovine leukemia and lymphoma are the severe, but uncommon sequelae of BLV infection. In this session, we will review the nature of the virus, along with the prevalence of the virus versus the prevalence of the disease. The available diagnostic tests will be reviewed, focusing on their interpretation. Finally, evidence-based control options will be presented.