At LNSP, the outbreak isolates were identified as V. cholerae [serogroup] O1, [serotype] Ogawa, and selected specimens were sent to CDC for confirmation and additional analyses. As of November 13, CDC had isolated V. cholerae from 14 specimens received from LNSP. All isolates were identified phenotypically and characterized by serotyping, biotyping, antimicrobial susceptibility testing, and by pulsed-field gel electrophoresis (PFGE), performed using a protocol developed by PulseNet International, the international molecular subtyping network for foodborne and waterborne disease surveillance. Additionally, the isolates were characterized genetically for the presence and subtype of certain virulence factors (e.g., the cholera toxin, genes specific for strains associated with the ongoing cholera pandemic, and antimicrobial resistance genes). The 14 isolates associated with the outbreak in Haiti were indistinguishable by all laboratory methods, revealing that the outbreak strain was V. cholerae serogroup O1, serotype Ogawa, biotype El Tor, and PulseNet PFGE pattern combination KZGN11.0092/KZGS12.0088. The strain possessed a cholera toxin variant that was first seen in cholera strains of the classical biotype. As of November 13, data indicated that a single strain caused illness among the 14 persons from Artibonite Department. If these isolates are representative of those currently circulating in Haiti, the findings suggest that V. cholerae was likely introduced into Haiti in one event. V. cholerae strains that are indistinguishable from the outbreak strain by all methods used have previously been found in countries in South Asia and elsewhere. PFGE analysis on isolates obtained from cholera patients who became ill in other departments in Haiti is ongoing.