Aromatic hydrocarbon resins with different molecular weights (M-w = 1300-50 400 daltons) were added to a solvent-based polychloroprene adhesive. The hydrocarbon resins were characterized using infra-red (IR) and differential scanning calorimetry (DSC) measurements. The properties and compatibility of the polychloroprene/resin blends were studied using mechanical tests, DSC measurements, scanning electron microscopy (SEM), and stress-controlled theology. Tack measurements were also carried out and the adhesion strength was obtained from T-peel tests on roughened styrene-butadiene rubber/polychloroprene adhesive joints. The addition of low-molecular-weight tackifiers produced a compatible polychloroprene/tackifier system (only one T-g was found in DSC measurements), while the addition of a high-molecular-weight (and broad molecular weight distribution) tackifier produced a partially incompatible system (two T-g＇s were found in DSC measurements). The compatibility of polychloroprene/tackifier blends was also assessed with stress-controlled rheology and SEM. An increase in the T-peel strength and tack were produced when the molecular weight of the tackifier increased, although the addition of a hydrocarbon resin with a M-w higher than about 50 000 reduced the tack. A broad molecular weight distribution in the tackifier favoured incompatibility with the polychloroprene, resulting in a reduction in the tack and rheological properties.