A newly described Vibrio cholerae O139 was isolated from a patient who had traveled in India on April 1993. The patient experienced 5 to 6 watery diarrhea per day after he returned to Japan. The isolated strain registered as K111 did not agglutinate with O1-O138 antiserum and agglutinated with O139 antiserum. This strain resembled V. cholerae O1 strain in biochemical characters and had ctx and zot, although was resistant to the vibrio static agent O/129. This is the first report of cholera-like illness by the newly described toxigenic V. cholerae O139 strain in Japan.