Vaccinia (smallpox) vaccine is an effective immunizing agent that brought about global eradication of naturally occurring smallpox, as declared by the World Health Organization in 1980. The United States ceased generalized smallpox vaccination in 1972 but reinstated it in 2002 for military personnel and selected healthcare workers (first responders who may be investigating possible cases of smallpox or caring for patients in selected hospitals) after the 2001 bioterrorism attacks. Since reinstitution of the vaccine, reports of transmission of vaccinia virus through contact with military smallpox vaccinees have been published, including four cases of female genital infection. We report a subsequent case of vulvar vaccinia infection acquired during sexual contact with a military vaccinee.