A polyesteramide copolymer having a glass transition temperature (Tg) of less than or equal to 0° C., contains at least one hard segment containing at least one amide bond, and at least one soft segment containing at least one ester bond. The soft segment is formed from at least one dimer fatty acid and/or dimer fatty diol and/or equivalent thereof. The copolymer is particularly suitable for use as a hot melt adhesive on low energy surfaces.