The invention provides an elastomer composition including an aromatic vinyl-isoprene block copolymer (a) having two or more poly(aromatic vinyl) blocks, in an amount more than 10 wt. % and less than 47.5 wt. %; an aromatic vinyl-isoprene diblock copolymer (b) in an amount more than 47.5 wt. % and less than 85 wt. %; and polyisoprene (c) having a weight average molecular weight of 20,000 to 100,000, in an amount more than 5 wt. % and less than 20 wt. %, wherein the composition has an aromatic vinyl monomer unit content more than 14 wt. % and less than 50 wt. %, based on the total amount of the components (a), (b), and (c).The elastomer composition is suitable for providing the pressure-sensitive adhesive composition, which exhibits excellent initial bond strength, peel strength, and holding power, and, even at relatively low temperature, exhibits minimal drop in initial bond strength and peel strength.