Study the sequencing of phzM and phzS genes and the effect of their mutation on phenazine production. Pseudomonas aeruginosa has the ability to adapt and grow in a variety of environments and is owing to its wide genetic flexibility. This organism produces a diverse group of phenazine including pyocyanin, phenazine-1-carboxylic acid and phenazine-1-carboxamide. The Phenazine-1-carboxylic acid that converted to pyocyanin is mediated by phzM and phzS novel phenazine modifying genes. The two genes that convert the phenazine-1-carboxylic acid to pyocyanin encode the putative enzymes, methyltransferase and monooxygenase, respectively, however, the overexpression of gene (s) encoding biosynthesis of pyocyanin via increasing the copy number has not so far identified in P. aeruginosa. Molecular technique was used to detect phenazine modifying genes (phzM, phzS), detection of mutations in these genes by sequencing. The results revealed that the phzM and phzS gene were present in 21(80.76%), 14(53.84%) respectively. Sequencing of phzM and phzS from isolates of P.aeruginosa reveal that 9 mutations in 8 isolates (7), (2) mutations for both genes respectively with the identities (99%) with the standard strand in NCBI web site.