The chemotaxis systems of Escherichia coli and Salmonella typhimurium are thought to be virtually identical. However, recently a putative chemotaxis gene, cheV, was found to be present in S. typhimurium but not in E. coli. Sequence analysis shows that the CheV protein shares sequence similarity to both CheW and CheY. My thesis research investigated whether cheV does play a role in S. typhimurium chemotaxis. My results show that disruption of the cheV gene had no effect on S. typhimurium's swarming ability and only a minor effect on the ability of S. typhimurium to sense/respond to serine and its ability to accomplish surface motility. My results also indicate that overexpression of the cheV gene disrupts S. typhimurium's swarming ability, as well as, S. typhimurium's ability to sense/respond to serine and S. typhimurium's ability to accomplish surface motility. Overall, these results suggest that CheV may be involved in S. typhimurium chemotaxis.