This study proposed a novel method to design diffractive multifocal lenses using phase retrieval, which was utilized to recover the phase information in imaging. The phase-retrieval lens could achieve the desired diffraction efficiencies at the targeted foci while maintaining a smooth profile and a high overall efficiency. An example of an optimum triplicator showed an overall efficiency of 92.59%, matching derivation of prior work. Another example of a nine-foci lens showed an overall efficiency of 98.74%. With its merits, the proposed method can design diffractive intraocular lenses with reduced dysphotopsia and increased manufacturability.