Provided are an injection preparation which include: an aqueous composition containing pemetrexed or a salt thereof, at least one antioxidant agent which is selected from the group consisting of ascorbic acid, an ascorbic acid derivative, and salts thereof, and the content of which is 0.0001 mass % to 0.5 mass % with respect to the total mass of the aqueous composition in terms of ascorbic acid, and an aqueous solvent of greater than or equal to 50 mass % with respect to the total mass of the aqueous composition; and a container which encloses the aqueous composition, in which the concentration of oxygen in gas within the container which encloses the aqueous composition is less than or equal to 0.2 volume %, and a method for producing the injection preparation.