We studied the restriction fragment length polymorphism of the rRNA gene and CTS genetic element in Vibrio cholerae O139 Bengal, which resurged in Calcutta in September 1996 after a gap of 32 months. While the strains from this resurgence were indistinguishable from the earlier strains by ribotyping, the structure of the CTX genetic element present in the current O139 strains was found to be unconventional.