A butene-1 polymer composition having MFR values of from 20 to less than 100 g/10 min., measured according to ISO 1133 at 190° C. with a load of 2.16 kg, made from or containing: A) a butene-1 homopolymer or a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of up to 5% by mole; and B) a copolymer of butene-1 with one or more comonomers selected from the group consisting of ethylene and higher alpha-olefins, having a copolymerized comonomer content of from 6% to 20% by mole; wherein the composition having a total copolymerized comonomer content from 4% to 15% by mole, referred to the sum of A) and B), and a content of fraction soluble in xylene at 0° C. of 75% by weight or less, determined on the total weight of A) and B).