We report the light-emitting properties of a liquid crystalline (LC) poly( 1,4-phenylenevinylene) derivative, poly[2,5-bis(dimethyloctylsilyl)-1,4-phenylenevinylene] (BDMOS-PPV) and the enhanced performance of polymer electroluminescent (EL) devices with multi-layer structure employing hole and electron transporting layers. The BDMOS-PPV showed a thermotropic LC behavior in a temperature range between 143 and 220degreesC. We investigated a polarized light-emission from BDMOS-PPV film. The multi-layer EL devices showed a dramatic improvement in EL output and quantum efficiency compared with the single-layer device. The maximum brightness of the multi-layer EL device was greater than 11000 cd/m(2) at the current density of 150 mA/cm(2).