Disclosed is an aqueous ink composition for dyeing polyamide-based fibers which comprises: at least one kind of dye arbitrarily selected from dyes of three categories including acid dyes, direct dyes and reactive dyes; a compound which is represented by formula (1) [wherein X1, X2, X3 and X4 independently represent each a hydrogen atom or a methyl group; and j, k, m and n represent numbers, provided that the sum thereof is 4 to 40 inclusive] and has an average molecular weight of 340 to 2200; and ethylene glycol. Also disclosed is a method for producing a dyed polyamide-based fiber which comprises a step for applying said aqueous ink composition to a polyamide-based fiber by using an inkjet printer. Thus, it is possible to provide a dye ink for dyeing polyamide-based fibers, which has a high ejection stability in a printer equipped with an industrial inkjet head requiring a high-viscosity ink, has a high storage stability of the ink and shows a good fixability to fibers.