Dip-pen nanolithography of ferroelectric PTO nanodots is described. This position-controlled dip-pen nanolithography using a silicon nitride cantilever produced an array of ferroelectric nanodots with a minimum lateral dimension of similar to 37 nm on a Nb-doped SrTiO3 substrate. This minimum-sized PTO dot is characterized by single-domain epitaxial growth with an enhanced tetragonality (c/a ratio) of 1.08.