Disclosed are a reactive hot melt adhesive composition having no problem in the initial adhesive strength, the adhesive strength obtained after moisture curing, stringiness and the like, and a method for producing the same. In the method, 1 to 50 parts by mass of a polymer (A), which is obtained by polymerization of a monomer composition including a vinyl monomer having a carboxyl group and a vinyl monomer having an epoxy group and has the equivalent ratio of the carboxyl group to the epoxy group in the range of 1/100 to 100/1, is mixed with 99 to 50 parts by mass in total of a polyisocyanate (B) and a polyol (C) so that the amount of the isocyanate group can become 1.1 to 10 moles relative to 1 mole of the hydroxyl group of the polyol (C), the sum of the components (A) to (C) being 100 parts by mass, and the resulting mixture is heated and mixed.