The electrical transport of photogenerated charge carriers in disordered polymer semiconductors is reviewed. We emphasize that the mobility parameter in these disordered semiconducting systems is not a well-defined quantity. We highlight the utility of scanning probe photocurrent technique on variety of polymers in an asymmetric-electrode patterned configuration. The multiple length and time scales present in carrier transport processes are indicated by the large observed decay length scales in these systems ©2009 IEEE.