A new room temperature photoresponsive side chain liquid crystalline polymer has been synthesized and tested. It. combines a side-on azobenzene LC with a low glass transition temperature polysiloxane backbone to obtain a nematic LCP at room temperature. The LCP also exhibits a crystalline phase that is kinetically trapped by the nematic phase at room temperature. Thermal transitions were observed at -7,42, and 73 degrees C for the T(g), T(m), and T(iso), respectively, and polarizing optical microscopy with in situ UV irradiation was used to characterize the room temperature photoresponsive behavior of its metastable nematic phase. Upon irradiation, the nematic phase almost completely disappeared in about 35 s. The isotropization was linear with a rate of 1.9 x 10(-11) mol/s at short times, but the final clearing process was exponential with a time constant of 4.6 s. These relatively short response times can be achieved at room temperature and are fast enough to be relevant for actuator and responsive elastomer applications.