We have determined, isolated, and characterized Pseudomonas which are involved in the biodegradation of phenanthrene, a polycylic aromatic hydrocarbon, from soil contaminated with fuel oil. Isolates were determined in the studied samples, 5 of which belong to Pseudomonas. Degradation of phenanthrene was established by forming clear zone around colonies on mineral salt medium and 4 Pseudomonas have ability to biodegrade phenanthrene. Morphological, physiological, biochemical, chemotaxonomic, and molecular characteristics of the Pseudomonas isolates were determined. Two of phenanthrene decomposing Pseudomonas were found to contain plasmid, having 2.7 kb molecular weight. This plasmids may play a significant role on the decomposition of phenanthrene. However, we think also that plasmid may be integrated to genom in plasmid-absent phenanthrene-degrading isolates.