Mixtures of peptides with various molecular weights and hydrophilic/hydrophobic balances (Peps) were prepared by enzymatic hydrolysis of casein composed of four proteins, and complexes of Peps with retinoic acid (Ret) were prepared in an attempt to enhance the water dispersibility of Ret. Ret-Pep complexes were prepared by mixing an acetone solution of Ret and an aqueous solution of Pep followed by lyophilization. The Ret-Pep complexes had higher apparent solubility Ret complexes prepared using polyethylene glycol and saccharides. Ret-Pep was present as a hydrocolloid with particle size of approximately 530 nm, and the surface charge was mainly dominated by Pep. Ret-Peps were prepared using different Peps obtained by ammonium sulfate fractionation and ultrafiltration. A fraction containing relatively hydrophobic peptides with high molecular weights showed much higher dispersibility for Ret than other fractions.