In the present contribution, we show that long-lived electrochemically generated chemiluminescence (ECL) from conjugated polymers can be achieved in both anodic and cathodic polarizations of poly [2-(2'-ethylethoxy)-5-methoxy-1,4-phenylene vinylene] (MEH-PPV), when the appropriate electrochemical conditions are adopted and an adequate degree of purity for the active polymer, solvent, and supporting electrolyte is achieved. The quantum efficiency is generally higher during the anodic polarization of MEH-PPV, whereas the ECL vs. time profile depends on the nature of the supporting electrolyte. Such findings led to the conclusion that the kinetics of the doping/undoping processes in MEH-PPV represents a crucial factor in determining the emissive properties of the conjugated polymer. A comparison of the ECL emission from analogous polymeric systems, namely poly[2,5-bis-(triethoxymethoxy)-1,4-phenylene vinylene] (BTEM-PPV) and poly[2,3-dibutoxy-1,4-phenylene vinylene] (DB-PPV), is also reported.