Graphitic　carbon　nitride　can　be　imprinted　with　a　twisted　hexagonal　rod-like　morphology　by　a　nanocasting　technique　using　chiral　silicon　dioxides　as　templates.　The　helical　nanoarchitectures　promote　charge　separation　and　mass　transfer　of　carbon　nitride　semiconductors,　enabling　it　to　act　as　a　more　efficient　photocatalyst　for　water　splitting　and　CO2　reduction　than　the　pristine　carbon　nitride　polymer.　This　is　to　our　knowledge　a　unique　example　of　chiral　graphitic　carbon　nitride　that　features　both　left-　and　right-handed　helical　nanostructures　and　exhibits　unique　optical　activity　to　circularly　polarized　light　at　the　semiconductor　absorption　edge　as　well　as　photoredox　activity　for　solar-to-chemical　conversion.　Such　helical　nanostructured　polymeric　semiconductors　are　envisaged　to　hold　great　promise　for　a　range　of　applications　that　rely　on　such　semiconductor　properties　as　well　as　chirality　for　photocatalysis,　asymmetric　catalysis,　chiral　recognition,　nanotechnology,　and　chemical　sensing.　©　2014　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim.