An overview of the electrochromism of conducting polymers is given. Conducting polymers are promising materials for electrochromic applications, not only as a colorant but also as a conducting material. Inorganic electrochromic materials can be combined with conducting polymers to extend the expected color change and reduce the operational potential. Conducting composites are one way to improve electrochromic properties and are also useful to improve physical properties. Several methods for the evaluation of conducting polymer electrochromism are also reviewed.