The process for producing N2-(1(S)-carboxy-3-phenylpropyl)-L-lysyl-L-proline in a simple, efficient and industrially advantageous manner, including the following steps: 1) subjecting N2-(1(S)-alkoxycarbonyl-3-phenylpropyl)-N6-trifluoroacetyl-L-lysyl-L-proline (1) to alkali hydrolysis in a mixed solution composed of water and a hydrophilic organic solvent using an inorganic base in an amount of n molar equivalents (n ≧ 3) per mole of the above compound (1), 2) neutralizing the hydrolysis product using an inorganic acid in an amount of (n − 1) to n molar equivalents (n ≧ 3) to form a compound (2) and removing the inorganic salt formed by causing the same to precipitate out from a solvent system suited for decreasing the solubility of the inorganic salt, and 3) causing the compound (2) existing in the mixture after removal of the inorganic salt to crystallize out at the isoelectric point thereof and thereby recovering the compound (2) in the form of crystals while retaining the salts including the trifluoroacetic acid-derived organic acid salt in a state dissolved in the mother liquor.