Poly(ethylene-co-vinyl acetate) (EVA) is an elastomeric material used widely in the food packaging industry. Many publications discuss the rheological, structural, barrier properties of pure EVA and EVA nanocomposites, but few deal with the significance of crystallinity and thermo-mechanical properties. This article discusses the thermo-mechanical properties of pure EVA. EVA is analogous to low density polyethylene where random branches occur and they are excluded from the crystal phase, and the polar co-monomer, vinyl acetate, is in the amorphous phase. Vinyl acetate provides enhanced tack and adhesion making EVA useful as melt adhesive, compatabilisers and in multi-layer films. The crystallinity in EVA is polyethylene crystallinity. EVA are thermally unstable since vinyl acetate units eliminate acetic acid leaving unsaturation in the main chain as sites for further degradation. In this study thermal degradation of EVA with vinyl acetate compositions to 33 %•w/w has been measured to determine whether high vinyl acetate levels lead to concerted release of acetic acid as occurs in poly(vinyl acetate). A combination of creep, recovery and modulated force thermomechanical measurements has been applied to the EVA compositions to interpret their transitions and relaxations. Thermal stability of EVA was found to be a function of vinyl acetate composition and quantitative loss of acetic acid occurred during thermal degradation. Temperature for acetic acid loss with vinyl acetate composition decreased exponentially indicating that vinyl acetate sequences contributed to concerted acetic acid elimination. Temperature and frequency dependence of storage and loss modulus transitions varied with vinyl acetate content.