An immunocompetent health care worker with no known history of varicella-zoster virus (VZV) disease was exposed to a patient with herpes zoster and was immunized 2 days later. Twenty-seven days after receiving the varicella vaccine, while hospitalized, she developed a disseminated rash. This exposure and subsequent development of symptoms posed infection control challenges. A polymerase chain reaction analysis of her vesicular fluid was positive for vaccine-type VZV, and a blood specimen collected before vaccination demonstrated a positive VZV titer by the fluorescent antibody to membrane antigen test. To the best of our knowledge, there have been no previous reports of an immunocompetent seropositive person developing vaccine-type VZV after receiving the vaccine.