The invention is provides a radiation-curable ink composition, an ink jet recording process and a recorded matter, wherein the radiation-curable ink composition can record an image excellent in flexibility, elongation resistance, abrasion resistance, and weather resistance. The radiation-curable ink composition includes an acrylate monomer of which homopolymer has a glass transition temperature of not higher than 0 DEG C. in an amount of 20% by mass or more and 65% by mass or less based on the total amount of reaction components; a monofunctional acrylate having an alicyclic structure; and a multifunctional acrylate having an alicyclic structure.