In this research, a contra-diffusion cell, which is an effective instrument for growing inorganic layers on porous substrates, was applied to prepare a thin layer of zeolitic imidazole framework-8 (ZIF-8) on polyvinylidene fluoride (PVDF) ultrafiltration membranes. With using of methanol as a solvent, a thin layer of ZIF-8 was fabricated resulted in a flexible inorganic coated organic membrane. The ZIF-8 nanoparticles were formed as a resistant layer on the outer surface and inner pores of PVDF support and its effect on permeability, flux recovery ratio (FRR) and treatment of colored wastewater was inves-tigated. Manufacturing parameters such as the reaction time between Zn2+ ions and imidazole ligands (16, 24 and 36 h) and concentration of PVDF in the casting solution of the support membranes (18, 20 and 22 wt%) were considered. The SEM images showed the well-growing of uniform and a thin layer of ZIF-8. The membrane performance tests revealed that ZIF-8 decorated membranes have higher pure water flux, BSA protein rejection and FRR related to the uncoated PVDF membrane. The fabricated mem-branes indicated high removal efficiency in three different MW dyes (Rhodamine B, Reactive Green 19 and Direct Black 38), with 75, 85 and 98% rejection, respectively. (C) 2022 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.