In Vibrio cholerae motility has an important role in virulence. Beside this flrA, flrB and flrC regulate the expression of both flagellar structure and function in Vibrio cholerae. Quorum sensing autoinducer molecules regulate the expression of EPS in Vibrio cholerae O139 Bengal strain MO10. The present study was conducted to investigate whether luxS gene (responsible for the synthesis of quorum sensing autoinducer molecule 2 i.e, AI-2) regulates motility as well as expression of both structural and functional regulatory genes flrA, flrB and flrC. In the peresent study we found that mutation in luxS gene caused reduction in motility and expression of flra was significantly decreased in the luxS mutant strain of the Vibrio cholerae O139 Bengal strain MO10 lac –. However expression of flrB and flrC remained unaltered by luxs gene. So luxS gene may regulate motility through the upregulation of flrA in Vibrio cholerae O139 Bengal strain MO10.