In recent years, the clinical and scientific interest in antibiotics known as polymyxin has increased greatly due to the large number of reports of multiresistant Gram-negative bacteria, among them Pseudomonas aeruginosa. This work aimed to investigate proteins responsible for resistance to polymyxins encoded in P. aeruginosa genomes using in silico tools. To do so, Escherichia coli MCR1 protein was used as bait. Sequences with similarities to MCR1 encoded in P. aeruginosa genomes were analyzed for physico-chemical properties including, theoretical molecular, isoelectric point, instability index, aliphatic index and hydropation index, secondary structures and protein domain. 31 Protein isoforms (EptA) more likely to confer resistance to polymyxin present in P. aeruginosa were determined. These proteins are between 465 and 521 amino acids in length. Molecular masses between 52.06 - 57.58 kDa, isoelectric point between 5.83 to 8.06, instability index between 60.33 to 66.42, aliphatic index between 99.980 to 107.39 and the hydropathy index between -0.038 to 0.037. These proteins belong to the DUF1705 superfamily with a Bit-score between 592,806 and 608,599. In conclusion the results evidenced the high degree of similarity between P. aeruginosa EpTAs including amino acids number, molecular mass, isoelectric point, instability index, aliphatic and hydrophobicity index, as well as secondary structures and protein domain with other proteins that confer resistance to polymyxins present in Gram-negative bacterial species of clinical interest. However, further studies are needed to identify the actual contribution of EptAs in P. aeruginosa species.