We describe a light-emitting device that is mechanically flexible; it can be sharply bent and curled without failure. These properties are obtained by using poly(ethylene terephthalate), PET, coated with a thin film of polyaniline as a flexible transparent hole-injecting electrode and soluble semiconducting polymer poly(2-methoxy,5-(2'-ethyl-hexoxy)-1,4-phenylenevinylene), MEH-PPV, as the emissive layer. The electroluminescent properties of this ''plastic'' light-emitting diode are the same as those of devices based on indium-tin oxide (ITO) hole injecting contacts, with a turn-on voltage of 2-3 Volts and an external quantum efficiency of about 1%.