Nanoscale ferroelectric honeycombs, comprised of vertically aligned PbTiO3 nanotubes, are fabricated by vapor phase reaction between lead acetate-infiltrated TiO2 nanotubes and PbO vapor. PbTiO3 nanohoneycombs converted by vapor phase reaction at 550 degrees C showed well-aligned nanoscale structure with alignment angle less than 1 degrees and well-defined ferroelectric properties with the effective piezoelectric coefficient of 44pm/V. This novel nanoscale structure is expected to facilitate high efficiency sensing of electromechanical and electrochemical stimuli.