A genome analysis of Pseudomonas pseudoalcaligenes KF707, a PCBs degrader and metal-resistant soil microorganism, revealed the presence of two novel gene clusters named che2 and che3, which were predicted to be involved in chemotaxis-like pathways, in addition to a che1 gene cluster. We herein report that the histidine kinase coding genes, cheA2 and cheA3, have no role in swimming or chemotaxis in P. pseudoalcaligenes KF707, in contrast to cheA1. However, the cheA1 and cheA2 genes were both necessary for cell swarming, whereas the cheA3 gene product had a negative effect on the optimal swarming phenotype of KF707 cells.