Contamination of the environment with polycyclic aromatic hydrocarbons is one of the major problems facing the industrialized nations today. In this work, Pseudomonas stutzeri CET 930 was studied for the first time as bioremediation agent for the degradation of effluents containing phenanthrene, pyrene and benzoanthracene, both individually and mixed. The promising results of degradation obtained at flask scale (92, 63 and 94% in 7 days, respectively) marks the onset of the operation at bench-scale bioreactor. The overall biotransformation of phenanthrene, pyrene and benzoanthrazene in batch operation mode was 95, 78 and 82 % when present individually, and 100, 98 and 100% when carrying out the biological process in cometabolic conditions. We have demonstrated the great versatility of this strain for the degradation of structurally different contaminants, such as metal working fluids, polycyclic aromatic hydrocarbons or insecticides such as chlorpyrifos, which makes it a suitable candidate to be applied at industrial scale. In all cases, the experimental data were successfully fitted to models, which turned out to be valuable tools to classify the metabolites involved in the biodegradation process as biomass-related. Since a complete mineralization was pursued, the metabolic pathways of the studied contaminants have been proposed based on gas-chromatography mass spectrometry data.