[en] This study aims at investigating the influence of Cr (VI) on growth of pseudomonas aeruginosa and Cr (VI) reduction in to Cr (III) on leather tannery effluent model by indigenous pseudomonas aeruginosa. The effect of Cr (VI) on pseudomonas aeruginosa growth was checked by growing the isolated in the medium containing certain concentration of sodium dichromat (K₂Cr₂O₇) as source of hexavalent chromium. Specthrophotometer analysis showed that the rate of pseudomonas aeruginosa growth decreased at the concentration of 100 ppm of hexavalent chromium (Cr (VI)). In addition, the reduction of Cr (VI) was monitored by growing the isolated in the medium with K₂Cr₂O₇. The result of AAS and specthrophotometer show the decreased of Cr (VI) concentration in the medium from 100 to 5.86 ppm with the conversion efficiency reach to 94.73% during 48 hours of the treatment. High efficiency conversion of Cr (VI) in to Cr (III) indicates the possibility of pseudomonas aeruginosa as promising bioremediation agent to reduce Cr (VI) in the environment. (paper)