A new strategy for fabricating highly ordered chitosan-Au core-shell nanopatterns with tunable surface plasmon resonance (SPR) properties is developed. This strategy combines fabrication of a chitosan nanopattern by using a soft-nanoimprint technique with selective deposition of Au nanoparticles onto the patterned chitosan surface. The SPR response can be tuned by controlling the features of the resulting Au shell/polymer hybrid pattern, which makes these materials potentially useful in ultrasensitive optical sensors for molecular detection.