Intrachain dynamics of charge carriers on isolated chains of a derivative of the pi-conjugated polymer, poly(thienylene-vinylene) (see Figure), in solution are investigated using time-resolved microwave conductivity measurements. High intrachain mobilities, of 0.23 +/- 0.04 and 0.38 +/- 0.02 cm(2) V-1 s(-1), are found for electrons and holes, respectively. It is observed that electrons become trapped at defects or impurities, in contrast to holes.