We report on site-selective growth of multiwalled carbon nanotubes (MWNTs) from a Co nanoparticle catalyst patterned by an ink-jet printing (IJP) technique. The dispersion of the Co nanoparticles was employed as "catalyst ink" for the IJP, and the catalyst pattern was subjected to chemical vapor deposition of acetylene gas. The patterned array of MWNTs was obtained with a dot size around 5-30 mum and showed field emission of electrons corresponding to the printed pattern. The present method offers a simple and powerful means to pattern carbon nanotubes at desired positions with any patterns. (C) 2003 American Institute of Physics.