<p>This paper aims at studying linear and non-linear rheology of neat high molecular weight polyethylene (HMWPE) and HMWPE filled with 2wt% magnetic graphene oxide nanofiller (GnPmFe₂O₃). GnPmFe₂O₃ was synthesized and characterized using FTIR analysis. The presence of Fe–O bonds and α-Fe₂O₃ (hematite) on the surface of GnPs was verified by distinct peaks. Nanocomposites of HMWPE/GnPmFe₂O₃ were prepared through melt mixing of 0, 1, 2, and 4wt% of GnPmFe₂O₃ nanoparticles and HMWPE. The prepared nanocomposites were sheeted at 200°C&#xa0;using a hot press in a magnetic field resulting in aligning the GnPmFe₂O₃ in HMWPE. The linear rheology&#xa0;indicated&#xa0;solid-like moduli at low frequencies with no terminal zone for HMWPE and 2wt% HMWPE/GnPmFe₂O₃and lower moduli for HMWPE/GnPmFe₂O₃. The complex viscosity displayed similar shear thinning trend, however, the consistency indexes were quite different with a higher value for HMWPE. Both samples showed a wide range of relaxation times. Most of the&#xa0;molecules relaxed within&#xa0;100s after removing the shear, however, a part of molecules needed longer times. The start-up experiments&#xa0;at various shear rates indicated further viscous behavior at low shear rates and more elastic one at high shear rates for both samples. The height of stress overshoots for HMWPE/GnPmFe₂O₃ was pretty lower than that of HMWPE. Applying a constant shear rate followed by the flow cessation and various rest times resulted in decreasing the height of stress overshoots&#xa0;with rest time for both samples. The results of flow reversal experiment after various rest times indicated higher stress overshoot for shorter times for both materials.</p> Graphical Abstract <p></p>