The optical rotatory dispersion and circularly dichroism of the chiral conjugated polymer polybithiophene prepared in a cholesteric liquid crystal are examined. Change in the optical rotation of the polymer depends on the redox conditions, with a maximum optical rotation of 3x10(4) deg/cm. The ellipticity of this polymer is also found to exhibit hysteresis with redox cycle. These results demonstrated that the optical rotation of the chiral polymer could be controlled via the electrochemical redox potential. (c) 2007 The Electrochemical Society.