PROBLEM TO BE SOLVED: To provide a remifentanil injection formulation which can prevent malpractice of injecting a wrong solution or diluent not containing remifentanil before mixed with remifentanil injection formulation in medical site, while having excellent long-term storage.SOLUTION: The above subject is solved by a remifentanil injection formulation which contains remifentanil and/or a physiologically acceptable salt thereof, and a coloring agent selected from cyanocobalamin, indocyanine green, and indigo carmine.