PROBLEM TO BE SOLVED: To provide an injection formulation which can suppress decomposition of pemetrexed or a salt thereof at the time of storage, and to provide a production method thereof.SOLUTION: The invention provides an injection formulation containing (i) pemetrexed or a salt thereof, (ii) at least one kind selected from the group consisting of glycerin and polyethylene glycol, and (iii) 50 mass% or more of an aqueous solvent to the total mass of the injection formulation and a production method thereof.