Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) analysis was performed to detect the genetic relationships between some Pseudomonas human pathogenic isolated from Hospital of Zagazig University. These isolates were fully characterized in Dept. of pharma. Microbiology, Faculty of pharmacy Zagazig University. Six out of 16 arbitrary decamer primers used in this study were informative and detected scoreable polymorphism in banding patterns of RAPD markersbetween these isolates and the wild type strain of P. aeruginosa PAOI and between some bacteriophages isolated from the environment propagating on Pseudomonas bacteria with the wild type phage F116 of P. aeruginosa. Each of primers used for analysis of individual bacterial isolates and bacteriophages amplified different number of bands. Genetic similarity between bacterial isolates and between bacteriophages, calculated as the total number of band differences. The highest similarity value(0.865) was found between PAO1 and both of ATC1,ATC78 andATC87.The lowest value (0.486) was found between PAO1andATC70.The dendrogram of genetic distances among bacterial isolates based on band polymorphisms generated by RAPD-PCR after using the primers showed that PAO1, ATC1, ATC78, ATC87 and ATC114 are fallen in one cluster, ATC45, ATC58, ATC76  and ATC111 are grouped in the second cluster, while ATC70 and ATC50 are found in the third cluster. All bacterial isolates except for ATC45 and ATC58 were distinguishable by unique RAPD markers. The highest similarity value(0.906)  between F116 and bacteriophage isolates was found between F116 and both of PA3 and PA9.The similarity coefficient value between F116 and AMSE2000 was (0.875).The dendrogram of genetic distances among bacteriophages based on band polymorphisms generated by RAPD-PCR after using  the primers showed that all bacteriophages except for PA5 and PA7 are fallen in one cluster. All bacteriophages except for AMSE2000, PA9 and  Ø111were distinguishable by unique RAPD markers. The data indicated that it could be possible to differentiate DNA polymorphism among bacterial isolates and  among bacteriophage isolates with relatively few markers. This study demonstrated the effectiveness of RAPDs for identifying polymorphism and can be useful in fingerprinting.