The incidence of severe invasive infections caused by Streptococcus pyogenes, a group A streptococcus (GAS), has increased in the past 10 years. Most cases occur outside of the hospital setting. We report on two patients with nosocomial streptococcal toxic shock syndrome (StrepTSS). In patient 1 the syndrome was associated with the development of necrotizing fasciitis following inguinal hernia repair. Patient 2 suffered from StrepTSS shortly after receiving a tetanus vaccine in her left deltoid. Epidemiologic investigations of these cases, which were noted within 48 hours of each other, showed that the same surgeon performed the vaccination on patient 2 after assisting a colleague during the hernia repair procedure on patient 1. He was found to be a nasal carrier of GAS. All GAS isolates from the patients and the surgeon were indistinguishable by pulsed field gel electrophoresis. PCR analysis demonstrated the presence of streptococcal pyogenic exotoxins A and F. All strains were of the T-1 serotype and possessed the gene for M-protein 1. This report demonstrates that a virulent strain of GAS may be spread by asymptomatically colonized medical personnel via the air route.