The synergistic effects of polyacrylonitrile (PAN) and nanokaolinite particles were studied using PAN/nanokaolinite mixed-matrix membranes (MMMs). Nanokaolinite was obtained from naturally available kaolin clay by an intercalation/exfoliation method. The kaolinite nanoparticles were added in varying compositions from 2.5 to 10 wt % at an increment of 2.5 wt % to PAN in the presence of the solvent N,N'-dimethylformamide (DMF). The uniform dispersion of nanokaolinite in the PAN matrix was achieved with the help of ultrasonication. The PAN/nanokaolinite material was characterized by attenuated-total-reflectance-infrared (ATR-IR) spectroscopy. Contact-angle measurements showed increased hydrophilicity due to the nanokaolinite addition that, in turn, helped reduce membrane fouling. Thermal stability and miscibility were characterized using thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The pure-water permeability flux increased from 122.8 to 264.93 L m(-2) h(-1) with increasing nanokaolinite concentration from 0 to 7.5 wt %. Rejection studies using protein showed an improved rejection efficiency of 92.7%, which is higher than that of the neat PAN membrane. PAN/nanokaolinite MMMs were also investigated in the separation of synthetic rhodamine B dye with and without the macroligand poly(diallyldimethylammonium chloride) (PDDA) for which the dye removal efficiency and flux were compared. Nanokaolinite-based MMMs are an inexpensive material and provide enhanced properties such as porosity, hydrophilicity, thermal stability, rejection, and productivity.