Three ethylene vinyl acetate (EVA) copolymers with different vinyl acetate (VA) contents (28-40 wt%) were mixed with rosin ester and polyterpene resin tackifiers in a 1:1 (weieht/weight) ratio. The theological and thermal properties of the tackifiers were determined and the use of theological measurements as a precise way to measure the softening point of the tackifiers is proposed. The glass transition temperature of the tackifiers was obtained from the second heating run, after the thermal history of the tackifiers was removed. The addition of the rosin ester to EVA produced a compatible mixture, whereas for the terpene resin a less compatible mixture was obtained. The increase in the VA amount decreased the crystallinity of EVA and both the storage and the loss moduli also decreased. but the peel strength and the immediate adhesion were increased. The immediate adhesion of EVA/tackifier blends was affected by both the compatibility and the rheologic al properties of the: blends. In fact, a relationship between the mechanical storage modulus (E') - obtained from DMTA experiments - of the adhesives and the immediate adhesion to thin rubber substrates was obtained. The adhesives containing the T tackifier showed higher moduli than those containing the G tackifier, and therefore higher peel strength values were obtained. An increase in the VA content increased the flexibility of the adhesives and thus a decrease in peel strength was obtained.