We report on the measurement of the pull-off force on nanoscale patterns that are formedby thermal nanoimprint lithography (t-NIL). Various patterns with feature sizesin the range of 50–900 nm were fabricated on silicon substrates using a rigiflexpolymeric mold of ultraviolet curable polyurethane acrylate (PUA, Young’s modulus ∼ 1 GPa) or perfluoropolyether (PFPE, Young’s modulus ∼ 10.5 MPa) and a resist layer of polystyrene (PS) of three different molecular weights (Mw = 18 100, 211 600 and 2043 000). The pull-off force was measured in non-polar, non-reactiveperfluorodecalin (PFD) solvent between a sharp atomic force microscopy (AFM) tip and animprinted pattern. Our experimental data demonstrated that the measured pull-off forceswere in good agreement with a simple adhesion model based on Lifshitz theory. Also, theforce on the pressed region (valley) is higher than that on the cavity region (hill), with theratio (hill/valley) decreasing with the decrease of pattern size and the increase of molecularweight. The confinement effects were more pronounced for smaller patterns (<300 nm) and highermolecular weights (Mw = 211 600 and 2043 000) presumably due to sluggish movement of polymer chains into nano-cavities.Finally, the experimental observations were compared with molecular dynamic simulationsbased on a simplified amorphous polyethylene model.