Abstract A laboratory experiment was conducted to isolate and diagnose bacterial isolates from Pseudomonas aeruginosa and test their efficiency in dissolving tri-calcium phosphate in solid cultures. 10 samples were collected from the soil and rhizosphere of different crops such as (coffee, barley, radishes, alfalfa) for several geographical regions, namely Thi-Qar, Muthanna, Qadisiyah and Najaf. Serial decimal dilutions of soil samples were carried out in order to isolate the bacteria, as King B medium was used to isolate the bacteria. The results showed obtaining bacterial isolates belonging to the bacteria Pseudomonas aeruginosa , which were diagnosed based on phenotypic traits and biochemical tests and by using special keys for diagnosis. With isolates P2, P10, and P1, the values were 2.46, 2.41, and 2.33, respectively, and the lowest values were represented by isolate 3P, which amounted to 21.4. The values of the other isolates varied in their phosphate solubility values, and the results indicated that there were no significant differences between P2 and P10.