The flammability characterization and synergistic flame-retardant effect of Fe-montmorillonite (Fe-OMT) in the ethylene-vinyl acetate/aluminum hydroxide (EVA/ATH) compounds were studied using limiting oxygen index (LOI), UL-94 test, cone calorimeter, microscale combustion calorimetry (MCC), and thermogravimetric analysis (TGA). The results showed that addition of Fe-OMT increases the LOI value and improves the UL 94 rating. Cone calorimeter data indicate that the addition of Fe-OMT greatly reduced the heat release rate and carbon monoxide production rate. Furthermore a compact char residue formed on the surface of the sample with a suitable of Fe-OMT during the combustion. The MCC results indicate that addition of Fe-OMT reduced the heat release rate and catalyzed the decomposition of EVA. The TGA data showed further evidence that Fe-OMT can catalyze carbonization reactions. POLYM. ENG. SCI., 2012. (C) 2011 Society of Plastics Engineers