Milker's nodules (pseudocowpox) are harmless skin lesions most commonly seen in persons whose occupation regularly brings them into close contact with cattle. They are caused by the paravaccinia virus, a member of the poxvirus family. Awareness of their clinical and histopathologic features is important, especially with today's heightened awareness of the threat of biologic warfare, to distinguish them from more worrisome entities such as tularemia and anthrax.