Cr(vi) is a heavy metal with a high toxicity level. Many levels of Cr(vi) in the environment are above the established quality standards. The membrane filtration method is a technique that can be used to reduce Cr(vi) levels because it is more effective and efficient compared to other methods. In this research, the ability of a PES membrane integrated with boehmite nanoparticles coated with polyphenolic compounds from Samanea saman bark extract (mixed matrix hollow fiber membrane PES/B-polyphenol) was studied in reducing Cr(vi) levels. The Cr(vi) removal carried out in this research used a membrane module, so test conditions were obtained that were similar to actual conditions. XRD, FTIR, PSA, tensile strength, and SEM-EDS characterization were carried out to study the characteristics of the membrane and nanofiller. The XRD diffractogram shows a specific peak for boehmite at 2θ = 14°. The results of FTIR characterization of B-polyphenols also identified the presence of Al-O functional groups at wave numbers 733, 603, 474 cm-1 for nanofillers and OH, C[double bond, length as m-dash]C, C-O, and C[double bond, length as m-dash]O functional groups for PES/B-polyphenol membranes. Based on SEM-EDS and tensile strength tests, it was observed that the Young's modulus value of the membrane was 56.67 MPa and had a porous surface that was evenly distributed. Mixed matrix hollow fiber membrane PES/B-polyphenols that have been fabricated can reduce Cr(vi) levels up to 92.12%. Mixed matrix hollow fiber membrane PES/B-polyphenols have a water flux 14.1 L m-2 h-1 with porosity is 85.3% and the contact angle formed between the membrane surface and water is 58-32°. Based on the results obtained, this mixed matrix hollow fiber membrane PES/B-polyphenol has potential to be applied on a larger scale regarding its application to reduce Cr(vi) levels.