Conducting polymers are promising materials which show attractive electric and optical properties with potential importance in advanced technologies. Electrochromism is one of the noteworthy characteristics of conducting polymers and is effective in forming conducting polymer images and patterns on an electrode. Space selective image formation is also possible without an electrode by means of the combination of photoinduced electron transfer reaction with electrochromism. This has potential as a novel method of surface modification for any geometry in any place and for micropatterning. In this article, some recent aspects of (1) the electrochromism of conducting polymers and (2) the polymerization and electrochromism of conducting polymers induced by photoillumination leading to image formation are considered from the materials viewpoint. Further, possible future applications for these materials and systems are commented upon.